minimum travel distance to fire escape

Fire Safety - Escape travel distances

Further guidance regarding escape routes.

This section provides further guidance on the general principles that apply to escape routes and provides examples of typical escape route solutions for a range of common building layouts. The guidance is based on premises of normal risk so if your premises (or part of your premises) are higher (or lower) risk you should adapt the solution accordingly.

Travel distances

Having established the number and location of people and the exit capacity required to evacuate them safely, you now need to confirm that the number and location of existing exits is adequate. This is normally determined by the distance people have to travel to reach them. In new buildings which have been designed and constructed in accordance with modern building standards the travel distances will already have been calculated. Once you have completed your fire risk assessment you need to confirm that those distances are still relevant. When assessing travel distances you need to consider the distance to be travelled by people when escaping, allowing for walking around furniture or display material etc. The distance should be measured from all parts of the premises (e.g. from the most remote part of an office or shop on any floor) to the nearest place of reasonable safety which is:

• A protected stairway enclosure (a storey exit)
• A separate fire compartment from which there is a final exit to a place of total safety.
• The nearest available final exit

Suggested travel distances

Where more than one escape route is provided:

• 25m in higher fire-risk area.
• 45M in normal fire-risk area.
• 60m in lower fire-risk area.

Where only a single escape route is provided:

• 12m in higher fire-risk area.
• 18m in normal fire-risk area.
• 25m in lower fire-risk area.

The travel distances given above are based on those recommended in Approved Document B of the Building Regulation and are intended to complement the other fire safety recommendations in Approved Document B. Your current escape route travel distances may be different from these since they may be based on recommendations made in alternative guidance. Where your route leads to more than one final exit, but only allows initial travel in a single direction (e.g. from a room or dead end), then this initial travel distance should be limited to that for a "single escape route". However, your total travel distance should not exceed that for "more than one escape route".

Measuring travel distances

The route taken through a room or space will be determined by the layout of the contents e.g. work stations, aisle layout. It is good practice to ensure routes to the exits are kept as direct and short as possible. In small rooms there may only be one exit but in larger rooms or area there may be many exits. In some cases where the contents are moved around or the space is liable to frequent change, e.g. in a storage area or where racking is moveable you should ensure that the exits, or the routes to them, do not become blocked or the length of the route is not significantly extended.

Escape travel distances

Further guidance regarding escape routes This section provides further guidance on the general principles that apply to escape routes and provides examples of typical escape route solutions for a range of common building layouts. The guidance is based on premises of normal risk so if your premises (or part of your premises) are higher (or lower) risk you should adapt the solution accordingly. Travel distances Having established the number and location of people and the exit capacity required to evacuate them safely, you now need to confirm that the number and location of existing exits is adequate. This is normally determined by the distance people have to travel to reach them. In new buildings which have been designed and constructed in accordance with modern building standards the travel distances will already have been calculated. Once you have completed your fire risk assessment you need to confirm that those distances are still relevant. When assessing travel distances you need to consider the distance to be travelled by people when escaping, allowing for walking around furniture or display material etc. The distance should be measured from all parts of the premises (e.g. from the most remote part of an office or shop on any floor) to the nearest place of reasonable safety which is: A protected stairway enclosure (a storey exit) A separate fire compartment from which there is a final exit to a place of total safety. The nearest available final exit Suggested travel distances Where more than one escape route is provided: 25m in higher fire-risk area. 45M in normal fire-risk area. 60m in lower fire-risk area. Where only a single escape route is provided: 12m in higher fire-risk area. 18m in normal fire-risk area. 25m in lower fire-risk area. The travel distances given above are based on those recommended in Approved Document B of the Building Regulation and are intended to complement the other fire safety recommendations in Approved Document B. Your current escape route travel distances may be different from these since they may be based on recommendations made in alternative guidance. Where your route leads to more than one final exit, but only allows initial travel in a single direction (e.g. from a room or dead end), then this initial travel distance should be limited to that for a "single escape route". However, your total travel distance should not exceed that for "more than one escape route". Measuring travel distance The route taken through a room or space will be determined by the layout of the contents e.g. work stations, aisle layout. It is good practice to ensure routes to the exits are kept as direct and short as possible. In small rooms there may only be one exit but in larger rooms or area there may be many exits. In some cases where the contents are moved around or the space is liable to frequent change, e.g. in a storage area or where racking is moveable you should ensure that the exits, or the routes to them, do not become blocked or the length of the route is not significantly extended.

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The LWF Blog

Fire safety engineering for design – means of escape design – part 100.

LWF’s Fire Safety Engineering blog series is written for Architects, building designers and others in the construction industry to highlight and promote discussion on all topics around fire engineering. In part 99, LWF considered the design and provision of alternative exits for means of escape based on criteria such as distance to be travelled and predicted occupancy. In part 100, we look at travel distances and how escape routes are protected with fire protection measures.

Travel distances are described in fire safety design codes as the maximum distance to be travelled by a building occupant to an exit. The travel distance must be measured as it would be walked, along the exit route and not in a straight line from one point to the exit.

Prior to the inside layout being planned for a building, the direct route from one point to the exit can be multiplied by 1.5 to give an approximation of the travel distance, which can be useful at that point in time.

Recommended maximum travel distances vary per occupancy type and also jurisdiction in which the project is built.

For example, the maximum recommended travel distance where escape is available in one direction only, for shops and commercial buildings is 18 metres according to ADB Volume 2, 15 metres from the Technical Handbook (Non-Domestic) and 23 metres from NFPA 101 (The US standard).

BS 9999 is the code of practice dealing with fire safety in the design, management and use of buildings. It allows for a risk-based approach to means of escape and travel distances which may allow longer travel distances than those prescribed in ADB Volume 2. The risk-based option is based on the geometry of the building and also the level of building management.

Fire protection measures for escape routes

Stairs on an escape route and some escape corridors need to be enclosed with fire-resisting construction to help prevent the passage of smoke and fire products into the escape route. A minimum fire resistance period of 30 minutes is recommended in most cases, although this may need to be increased in certain instances, for example, if the stairway also acts as a protected shaft providing separation between levels.

To help with preventing the ingress of smoke into protected escape routes, all elements should be sealed against smoke and doors should be fitted with smoke seals.

In part 101 of LWF’s series on fire engineering, we will continue to discuss fire protection measures for escape routes, starting with protected lobbies. In the meantime, if you have any questions about this blog, or wish to discuss your own project with one of our fire engineers, please contact us.

Lawrence Webster Forrest has been working with their clients for over 25 years to produce innovative and exciting building projects. If you would like further information on how LWF and fire strategies could assist you, please contact the LWF office on 0800 410 1130.

While care has been taken to ensure that information contained in LWF’s publications is true and correct at the time of publication, changes in circumstances after the time of publication may impact on the accuracy of this information.

How Many Fire Exits does a Building Need?

Size and usage can make a difference to the number of fire exits a building requires. But a fire exit is far more than just a door – and creating a fire safety strategy can help businesses prepare for any scenario.

Best Practice and Minimum Standards

Government guidelines don’t state the number fire exits required for businesses, but fire safety regulations do give best practice and minimum requirements for business owners to follow.

More than One

If possible, more than one fire exit is recommended. All fire exit doors need to be completely independent of each other, with distinct escape routes that provide multiple opportunities to evacuate the building.

In any building, the distance to a fire exit needs to be as short as possible. In a structure with multiple fire exits, nobody should be more than 60 metres away from a fire exit . If your business premises is used for industrial work that has a high risk of fire , that maximum distance drops to 25 metres .

It’s not always going to be possible to provide more than one fire exit; for instance in small buildings or irregular heritage structures. In these scenarios, the guidance says that there should be n o point more than 25 metres away from the main fire exit – but if your industry is at high risk from fire, the maximum distance is cut to 12 metres .

A Fire Escape is Much More than a Door

The route to the fire exit is as important as the door itself. Without a protected means of escape , accessing a fire exit could become impossible if fire encroached on the escape route.

With safe routes leading to fire escapes, the chances of surviving in an emergency are drastically improved. We’re not just talking about keeping corridors clear of obstructions, here; a protected means of escape needs to be shielded from fire and smoke, ventilated, lit and clearly signposted.

Without a properly signposted protected means of escape, people become trapped. Panic during an emergency can cause otherwise rational and logical people to make terrible survival choices. But creating a route, especially in large open-plan settings, can be a challenge.

Create a Protected Means of Escape with Fire Curtains

Fire curtains can be used to protect a means of escape, which could prevent the catastrophic loss of life and even reduce structural damage, business downtime and financial losses.

A protected means of escape needs to be part of your fire strategy , whether your premises is a purpose-built facility or a repurposed building. In most cases, your local authority can provide specific information on regulations for building types and businesses – but in some cases, a special consultant may be required.

At Coopers Fire, we help organisations around the world meet and exceed their fire safety goals – with decades of experience in our field.

Saving Lives and Protecting Businesses from Fire

Protecting buildings and those in them from fire and smoke is our mission at Coopers Fire. We design and manufacture life-saving fire curtains for a huge range of industries and building types.

Our expertise has led us to become a world leader in fire safety. For more information on our non-intrusive, life-saving fire and smoke protection, or our educational training courses, call us on 02392 454 405 or email [email protected] .

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Claire Rizos

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Whitepaper: enhancing security, resilience and efficiency across a range of industries, how many fire exits are required in a building.

Under usual circumstances a building is designed for a particular purpose, and the design and build process is well regulated with the outcome being a structure that remains more or less suitable during its lifetime.

But sometimes a building’s use may change and we may need to reconsider the suitability of the fire exits.

Examples of the times when we need to consider the suitability of exits are:

• An increase in capacity, e.g. a former office becoming used as a conference space, a storage area being converted to a shop;
• A change of use to a higher fire risk category;
• Where exits have been permanently obstructed;
• Temporary building works which might require closure of some routes;
• When temporary facilities such as marquees are erected;
• When building alterations or new buildings are proposed.

Where should you look for guidance? There are a number of sources of advice for those in the UK. Although the Building Regulations apply to new buildings and alterations, they’re a good source of information. The Building Regulations Approved Document B covers the fire safety design of buildings in England and Wales. (In Scotland the equivalent is the Technical Handbook (Non-domestic) Section 2 – Fire and in Northern Ireland, NBS Technical Booklet E.)

Other places to look are the sector-specific guides to fire risk assessment issued by the Department of Communities and Local Government (and equivalents issued in Scotland ) and BS9999, “Code of practice for fire safety in the design, management and use of buildings.”

What are the considerations? In common with other sources of guidance on the subject, Approved Document B states:

The number of escape routes and exits to be provided depends on the number of occupants in the room, tier or storey in question and the limits on travel distance to the nearest exit.

There is a core principle that there should normally be at least two escape routes. However, exceptions are allowed where travel distances are short and numbers are low.

It wouldn’t be possible in a short article to explain every intricacy but taking an example of a single storey office, it could have a single entrance/exit provided the actual travel distance from the furthest point to the exit was less than 18 metres and there were less than 60 people using the office.

A note on “alternative exits” As you’d expect, there are criteria as to what constitutes an alternative i.e. the routes must be more than 45 degrees apart (for a diagram, check out page 34 of Approved Document B ).

The following table gives a general guide to the numbers of exits required by capacity:

Recommended door width Of course, it isn’t simply a matter of any old door does the job no matter what size, so as you’d expect there’s guidance on the design width of exits. Unfortunately, though, the available guidance differs greatly so that Approved Document B, for example, is not the same as BS9999 and is different again from the Department of Communities and Local Government (DCLG) guides. Here’s the table from the Approved Document B:

In the DCLG guidance a 750mm door width in a normal fire risk premises has a capacity of 100 people and a 1050mm door can take 200. How do you decide which to use? Well, the Building Regulations apply to new builds and alterations, and the DCLG guidance applies to existing premises.

Where all the various guides are in agreement is that you should discount one exit, i.e. assume that a fire is affecting the largest of the alternative exits, and then make sure that the capacity of the remaining exits is sufficient. (If two exits are close together, you should discount both.)

Taking an example of an assembly room with a capacity of 200, you could fulfill the requirement of Approved Document B with two exits of a minimum dimension of 1050mm each or three at least 850mm wide.

Caution Guidance should not be applied rigidly, so, for example, if there is a higher risk of fire or the occupants are at greater risk, then the acceptable travel distances reduce and you may need more exits. The most thorough way to apply these variances is to use BS9999, but it isn’t a document to cherry-pick from — you either apply the whole system to your fire strategy or leave it alone.

Answering the basic question how many fire exits we need in a building? I should say this depends on many factors. Some of them include the no of individuals on the building, the no of normal exits on the building, evacuation time to evacuate the building in case of emergency.

You’re right of course, the travel distances and directions given in the standards are an attempt to take these factors into account.

Evacuation time should be pretty swift – 6-10 minutes are targets I’ve heard. The amount of exits should be commensurate to allowing this.

Don’t get confused with the difference between rooms and buildings. The 45 degree rule only applies inside a room, however it is not that simple. The two exits cannot lead onto the same route, so two exits from a room may be more than 45 degrees appart but if they lead onto the same corridor and there is no seperation between the doors in the corridor it only counts as one exit. The reason being a fire in the corridor would knock out both doors. Outside the room you need to look at fire seperation, protected routes and places of …  Read more »

Shame this article is headed up with signs which are now non-compliant. BS 5266 changed over a year ago and few people seem to know about the move back to BS 5499 type signs which comply with the new ISO 7010.

It’s only a visualisation to give the impression of the potential confusion over exits, not a recommended use of signage, but absolutely take your point, Mike, thanks for pointing this out.

Thanks for you comment, Mike, important advice. It’s also important that people remember there really is no hard and fast rule, and that risk assessments and simulations unique to a building are the best way to make sure you’ve covered the bases.

ISO7010 doesn’t make existing signs non-compliant however – just in case anyone interprets this conversation that way!

Thank you Claire. Very informative and to the point article. The only thing I would add there is that in the premises that are covered by the RRO (Fire Safety) and Building Regulations doors used as the final point of exit should be fire resisting. This is because fire started in the exit door area would effectively cut off the main escape route from the premises. If risk of fire is applicable to the areas located on both sides of the door, such as the entrance/exit doors of flats that are facing the common areas in HMOs, this means making it …  Read more »

Following a guide tends towards compliance but does not guarantee compliance. The only way to ensure compliance is to carry out a risk assessment and deal with matters that arise from it. Even the building regulations require a risk assessment to be done. Blindly following the guides can be a disaster even when they are over-engineered to cope with most situations. The are so many variable factors which often change over time such that it would be impossible in a guide to cover all eventualities. Just taking the basic concept that 40 people can pass through a unit of exit width in one minute can …  Read more »

Thanks Claire for an interesting article . There are so many factors to be considered for the provision of exits and any fire risk assessor of course knows that it’s a core principle of fire safety when commenting on means of escape. Article 14 of the FSO has many sub-sections to ensure that the escape routes and exits within a building are sufficient in type, width, number, location and that the exit doors are fitted with the correct door furniture and open in the right direction where necessary. I’m struggling with the comment posted that the final exit door needs …  Read more »

I work at a petrol station and we only have one fire exit. The back door fire as been blocked off. If there ever a fire on forecourt we cannot get out as our only way out leads onto forecourt. Is that wrong.

I’ve been there 1 year and 4 month never had a fire drill training

I am appalled that the architects and owners and building department governing the Grenfell Tower approved a renovation that would remove a stairwell in order to add rentable space. How can this be permitted in the country that CREATED fire codes in response to the Great Fire of 1666?

Here is the scenario: You work in small office room that can hold up to 11 work stations. There is only one way in and one way out. No windows.Just the entrance and exit door. Now, a fire breaks out in the hallway of that door. you can’t escape because it’s right outside the exit door. What are you and your co-workers to do, there is no other way out of the office space??? No windows, no other exit door!!!!

Hey I know that you’ve discussed most of it in regards of the fire regs ..I was just wondering what is the typical distance from the room to the fire exits? I had various answers and so it made me confused.

My daughter is just renting a flat on top floor ,of a three story building . Is there a legal requirement for a fire escape ,as there isn’t one ?

Hi Joan. Sorry for slow response. .Did you find out about this? I know a fire safety expert who can give you advice if you need it…

This is some good information to know. I think that is our building, we don’t have enough signs. I’ll for sure let my boss know so that we can get some new ones installed as soon as possible.

What measures need to be temporarily taken when one exit (out of two) is out of use for a while due to repair works. In this instance in a private residential building with few residents who are very familiar with the building.

This will also depend on the travel distance to a place of safety.

the distance between exits horizontally – on level floor how is this worked out

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Occupational Safety and Health Administration

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• 1910.36 - Design and construction requirements for exit routes.
• Part Number: 1910
• Part Number Title: Occupational Safety and Health Standards
• Subpart: 1910 Subpart E
• Subpart Title: Exit Routes and Emergency Planning
• Standard Number: 1910.36
• Title: Design and construction requirements for exit routes.
• GPO Source: e-CFR

Basic requirements . Exit routes must meet the following design and construction requirements:

An exit route must be permanent . Each exit route must be a permanent part of the workplace.

An exit must be separated by fire resistant materials . Construction materials used to separate an exit from other parts of the workplace must have a one-hour fire resistance-rating if the exit connects three or fewer stories and a two-hour fire resistance-rating if the exit connects four or more stories.

Openings into an exit must be limited . An exit is permitted to have only those openings necessary to allow access to the exit from occupied areas of the workplace, or to the exit discharge. An opening into an exit must be protected by a self-closing fire door that remains closed or automatically closes in an emergency upon the sounding of a fire alarm or employee alarm system. Each fire door, including its frame and hardware, must be listed or approved by a nationally recognized testing laboratory. Section 1910.155(c)(3)(iv)(A) of this part defines “listed” and § 1910.7 of this part defines a “nationally recognized testing laboratory.”

The number of exit routes must be adequate -

Two exit routes . At least two exit routes must be available in a workplace to permit prompt evacuation of employees and other building occupants during an emergency, except as allowed in paragraph (b)(3) of this section. The exit routes must be located as far away as practical from each other so that if one exit route is blocked by fire or smoke, employees can evacuate using the second exit route.

More than two exit routes . More than two exit routes must be available in a workplace if the number of employees, the size of the building, its occupancy, or the arrangement of the workplace is such that all employees would not be able to evacuate safely during an emergency.

A single exit route . A single exit route is permitted where the number of employees, the size of the building, its occupancy, or the arrangement of the workplace is such that all employees would be able to evacuate safely during an emergency.

Note to paragraph (b) of this section: For assistance in determining the number of exit routes necessary for your workplace, consult NFPA 101-2009, Life Safety Code, or IFC-2009, International Fire Code (incorporated by reference, see § 1910.6).

Exit discharge .

The door that connects any room to an exit route must swing out in the direction of exit travel if the room is designed to be occupied by more than 50 people or if the room is a high hazard area ( i.e. , contains contents that are likely to burn with extreme rapidity or explode).

The capacity of an exit route may not decrease in the direction of exit route travel to the exit discharge.

Note to paragraph (f) of this section: Information regarding the “Occupant load” is located in NFPA 101-2009, Life Safety Code, and in IFC-2009, International Fire Code (incorporated by reference, see § 1910.6).

An outdoor exit route is permitted . Each outdoor exit route must meet the minimum height and width requirements for indoor exit routes and must also meet the following requirements:

[FR 67 67962, Nov. 7, 2002; 76 FR 33606, June 8, 2011; 79 FR 76897, Dec. 23, 2014]

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Part D1 Provision for escape

Deemed-to-satisfy provisions, d1.0 deemed-to-satisfy provisions.

Where a Deemed-to-Satisfy Solution is proposed, Performance Requirements DP1 to DP6 , DP8 and DP9 are satisfied by complying with—

D1.1 to D1.17 , D2.1 to D2.25 and D3.1 to D3.12 ; and

in a building containing an atrium , Part G3 ; and

in a building in an alpine area , Part G4 ; and

for a building containing an occupiable outdoor area , Part G6 ; and

for additional requirements for Class 9b buildings, Part H1 ; and

for public transport buildings, Part H2 ; and

for farm sheds , Part H3 .

Where a Performance Solution is proposed, the relevant Performance Requirements must be determined in accordance with A2.2(3) and A2.4(3) as applicable.

Performance Requirement DP7 must be complied with if lifts are to be used to assist occupants to evacuate a building.

There are no Deemed-to-Satisfy Provisions for this Performance Requirement in respect of using lifts.

To clarify that the requirements of DP1 to DP6 , DP8 and DP9 will be satisfied if compliance is achieved with Parts D1 , D2 and D3 in the case of all buildings, Part G3 in the case of buildings with an atrium, Part G4 in the case of buildings in alpine areas, Part G6 in the case of occupiable outdoor areas, Part H1 in the case of theatres, stages and public halls, and Part H2 for public transport buildings. DP7 is only required to be complied with if lifts are to be used to assist occupants to evacuate.

Where a solution is proposed to comply with the Deemed-to-Satisfy Provisions, D1 clarifies that for most buildings compliance with Parts D1 , D2 and D3 will achieve compliance with DP1 to DP6 , DP8 and DP9 . The exceptions to this general rule are set out below.

If the building contains an atrium, it must comply with Part G3 in addition to Parts Parts D1 , D2 and D3 .

If the building contains an occupiable outdoor area, it must comply with Part G6 in addition to Parts D1 , D2 and D3 .

A building which comprises a theatre, stage or public hall must comply with Part H1 in addition to Parts D1 , D2 and D3 .

If the building contains an atrium and one or more of a theatre, stage or public hall, it must comply with Parts D1 , D2 , D3 , G3 and H1 .

A building located in an Alpine Area must comply with Part G4 in addition to Parts D1 , D2 and D3 .

A building associated with public transport services, such as railway stations, bus interchanges, airports and ferry terminals must comply with Part H2 in addition to Parts D1 , D2 and D3 .

Where a Performance Solution is proposed, the relevant Performance Requirements must be determined in accordance with A2.2(3) and A2.4(3) as applicable. (See commentary on Part A2 ).

D1.1 Application of Part

The Deemed-to-Satisfy Provisions of this Part do not apply to the internal parts of a sole-occupancy unit in a Class 2 or 3 building or a Class 4 part of a building.

To exempt internal parts of sole-occupancy units in Class 2 and Class 3 buildings and Class 4 parts from the Part D1 Deemed-to-Satisfy Provisions.

The Part D1 Deemed-to-Satisfy Provisions do not apply within a sole-occupancy unit of a Class 2 or Class 3 building and Class 4 parts.

This is because most occupants are familiar with the layout of their unit. The units are small in area compared to sole-occupancy units in other classes of building. They will also have a low level of occupancy and a lower fire load than most commercial and industrial buildings.

Additionally, such units will be separated from the rest of the building by fire-rated construction, or sprinklers will be installed. Except when considering smoke-hazard management matters, the path to the door leading out of sole-occupancy units is not regarded as part of the path of travel to an exit. See Part E2 .

D1.2 Number of exits required

All buildings — Every building must have at least one exit from each storey .

Class 2 to 8 buildings — In addition to any horizontal exit , not less than 2 exits must be provided from the following:

Each storey if the building has an effective height of more than 25 m.

A Class 2 or 3 building subject to C1.5 .

SA D1.2(b)(iii) and (iv)

Basements — In addition to any horizontal exit , not less than 2 exits must be provided from any storey if egress from that storey involves a vertical rise within the building of more than 1.5 m, unless—

the floor area of the storey is not more than 50 m 2 ; and

the distance of travel from any point on the floor to a single exit is not more than 20 m.

Class 9 buildings — In addition to any horizontal exit , not less than 2 exits must be provided from the following:

Each storey if the building has a rise in storeys of more than 6 or an effective height of more than 25 m.

Any storey which includes a patient care area in a Class 9a health-care building .

Any storey that contains sleeping areas in a Class 9c building.

Each storey in a Class 9b building used as an early childhood centre .

Each storey in a primary or secondary school with a rise in storeys of 2 or more.

Any storey or mezzanine that accommodates more than 50 persons, calculated under D1.13 .

NSW D1.2(d)(vii)

Exits from Class 9c buildings and patient care areas in Class 9a health-care buildings — In a Class 9a health-care building and a Class 9c building, at least one exit must be provided from every part of a storey which has been divided into fire compartments in accordance with C2.2 or C2.5 .

Exits in open spectator stands — In an open spectator stand containing more than one tier of seating, every tier must have not less than 2 stairways or ramps, each forming part of the path of travel to not less than 2 exits .

Access to exits — Without passing through another sole-occupancy unit every occupant of a storey or part of a storey must have access to—

an exit ; or

at least 2 exits if 2 or more exits are required .

To require the provision of sufficient exits to enable safe egress in case of an emergency.

Under D1.2(a) , all buildings must have at least one exit from each storey. The remainder of D1.2 sets out the circumstances in which more than one exit may be required.

The purpose of regulatory control over the number of exits in a building is to maximise the opportunities for people to have egress from the building in an emergency.

Egress from some buildings can be very difficult (for example, particularly tall or large buildings, or even small buildings which have a complex passageway design). It may be necessary to provide several alternative exits.

While a number of the D1.2 provisions refer to “horizontal exit”, they do not require the installation of a horizontal exit. Rather, where a horizontal exit exists or is proposed, at least two additional exits must be provided. Where there is no horizontal exit, there must still be at least two exits.

The D1.2(b)(i) provision regarding an effective height of 25 metres recognises the effective operating height for fire brigade ladders and other fire-fighting and rescue equipment. Above this height, fire-fighting, rescue and egress problems increase considerably.

C1.5 provides a concession for Class 2 and Class 3 buildings (having a rise in storeys of two), in that if they comply with certain conditions they may be of Type C construction. In order to qualify for that concession such buildings must have at least 2 exits.

This provision recognises that Class 2 and Class 3 buildings constructed in accordance with C1.5 include additional evacuation provisions.

“Basement” is not defined in the BCA. A basement is regarded as a below-ground-level storey not counted in the rise in storeys.

Any basement in excess of the minimum floor area specified in D1.2(c)(i) which has a travel distance to an exit in excess of that specified in D1.2(c)(ii) , must have at least two exits. The reason for this is that basements present difficulties in terms of egress and fire-fighting. These include:

• the difficulty in naturally venting smoke from a fire because of the lack of windows; and
• the need for occupants to evacuate in the direction of smoke travel. This is the opposite to upper storeys, where people would be evacuating downwards and the smoke travelling upwards.

D1.2(d)(i) covers Class 9 buildings with a rise in storeys of more than six (additional to the provisions which apply to Class 2 to Class 8 buildings) and Class 9 buildings with an effective height of more than 25 metres (which is the same as for Class 2 to Class 8 buildings, and recognises the effective operating height for fire brigade ladders and other fire-fighting and rescue equipment).

D1.2(d)(i) recognises the emergency egress requirements for Class 9 buildings. Such buildings could contain large numbers of people who may be unfamiliar with the building’s egress provisions. They might also be confused and in various stages of immobility.

D1.2(d)(i) does not refer to “whichever is the lesser”, nor, for that matter, “whichever is the greater”—meaning that both are applicable.

In D1.2(d)(ii) – (vi) , and D1.2(e) and (f) , the BCA recognises that some Class 9 buildings (patient care areas, aged care buildings, early childhood centres, schools, spectator stands, storeys or mezzanines containing more than 50 people as calculated under D1.13 ) present difficult evacuation conditions (requiring two exits additional to any horizontal exits) because of such factors as:

• the age and nature of the occupants;
• the density of occupation (for example, occupants per m 2 ); and
• the unfamiliarity of occupants with the emergency evacuation requirements.

There is little point requiring exits if they are not accessible at all times. D1.2(g) requires that occupants must be able to access an exit. Where two or more exits are required, at least two exits (allowing for the fact that one of the exits may be made inaccessible by an emergency, such as a fire) should be accessible.

Such access must not be through another sole-occupancy unit because access to the unit may be locked or barred.

D1.3 When fire-isolated stairways and ramps are required

Class 2 and 3 buildings — Every stairway or ramp serving as a required exit must be fire-isolated unless it connects, passes through or passes by not more than—

3 consecutive storeys in a Class 2 building; or

2 consecutive storeys in a Class 3 building,

and one extra storey of any classification may be included if—

it is only for the accommodation of motor vehicles or for other ancillary purposes; or

the building has a sprinkler system (other than a FPAA101D system) complying with Specification E1.5 installed throughout; or

the required exit does not provide access to or egress for, and is separated from, the extra storey by construction having—

an FRL of –/60/60, if non- loadbearing ; and

an FRL of 90/90/90, if loadbearing ; and

no opening that could permit the passage of fire or smoke.

Class 5, 6, 7, 8 or 9 buildings — Every stairway or ramp serving as a required exit must be fire-isolated unless—

in a Class 9a health-care building — it connects, or passes through or passes by not more than 2 consecutive storeys in areas other than patient care areas ; or

it is part of an open spectator stand ; or

in any other case except in a Class 9c building, it connects, passes through or passes by not more than 2 consecutive storeys and one extra storey of any classification may be included if—

an FRL of 90/90/90 for Type A construction or 60/60/60 for Type B or C construction, if loadbearing ; and

SA D1.3(b)(iv)

To indicate when fire-isolated stairways and ramps are required to enable safe egress in case of a fire.

D1.3 and DP5

D1.3 comprises the Deemed-to-Satisfy Provisions for DP5 .

Fire-isolated exits are required in multi-storey buildings to enable people to evacuate past a storey on fire. They also help the fire brigade carry out search and rescue and fire-fighting.

Such exits minimise the distance people need to travel in a fire-affected area before accessing a “safe place”, such as a fire-isolated stairway.

Fire-isolated exits may be:

• fire-isolated stairways;
• fire-isolated ramps; and
• fire-isolated passageways connected to fire-isolated stairways or ramps.

D1.3 sets out when stairways and ramps connecting storeys in a building are required to be fire-isolated. This only applies to a stairway or ramp serving as a required exit. Therefore, from the definition of "exit", D1.3 only applies to those providing egress to a road or open space. Combined with the provisions of D1.2 that exits are required from every storey, a stairway or ramp serving as an exit will generally be connecting storeys. However, the term "exit" could also apply to a stairway or ramp from a basement that exits vertically, directly to a road or open space and thus, does not technically connect storeys.

D1.3 only applies to stairways that are required exits and therefore does not apply to stairways between split levels of a single storey of a building or those leading from the front door of a building.

Under certain specified conditions, D1.8 permits the use of external stairways in place of fire-isolated stairways.

D1.3(a)(i) permits Class 2 buildings to have non-fire-isolated exits provided they do not connect, pass through or pass by more than three consecutive storeys, plus an extra storey of any classification under specified conditions. The terms “connect”, “pass through” and “pass by” include the following situations:

• Where the exit provides access to the storey.
• Where the exit passes through the storey but does not necessarily provide access to or egress for the storey.
• Where the exit is external to the building, i.e. passes by the storey but does not necessarily provide access to or egress for the storey.

With regard to the allowance for 3 storeys, the BCA assumes that residents of Class 2 buildings tend to be long-term occupants, and aware of their surroundings. This makes them likely to be able to exit quickly without the need for fire-isolated exits.

An extra storey of any classification may be included under certain circumstances where the fire risk associated with the extra storey is low. The circumstances are:

• where the extra storey is used for a carpark or other ancillary purposes. In Class 2 buildings a carpark usually represents a low fire risk, and is unlikely to have many occupants for any length of time. The inclusion of the extra storey applies when the building only consists of a Class 2 building and a carpark. The building may also include a Class 3 part, however in such a case, the Class 3 portion of the building would control the number of storeys connected by a non-fire-isolated exit (see comments on D1.3(a)(ii) ); and
• where the building contains a sprinkler system. This concession recognises the ability of sprinkler systems to extinguish or contain a fire thereby allowing additional time for occupants to escape; and
• where the exit is separated from the extra storey by walls having an FRL consistent with those required for a public corridor in a Class 2 or 3 building. By having separating walls with an FRL and by preventing any connection to the extra storey for the purpose of providing access to or egress for that storey, the non-fire-isolated exit is protected from the fire risk associated with the extra storey.

D1.3(a)(ii) permits Class 3 buildings to have non-fire-isolated exits provided they do not connect, pass through or pass by more than two consecutive storeys, plus an extra storey of any classification under specified conditions. The terms “connect”, “pass through” and “pass by” include the following situations:

The allowance for two storeys is based on residents of a number of Class 3 buildings being less familiar with the building layout and paths of travel to an exit than residents of a Class 2 building. The differential between Class 2 and Class 3 buildings recognises a higher potential level of risk in Class 3 buildings.

• where the extra storey is used for a carpark or other ancillary purposes. In Class 3 buildings a carpark usually represents a low fire risk, and is unlikely to have many occupants for any length of time. The inclusion of the extra storey applies when the building only consists of a Class 3 building and a carpark. The building may also include a Class 2 part, however in such a case, the Class 3 portion of the building would control the number of storeys connected by a non-fire-isolated exit; and
• where the building contains a sprinkler system. This concession recognises the ability of sprinkler systems to extinguish or contain a fire; and

Under D1.3(b)(i) , required exits in Class 9a health-care buildings need to be fire-isolated if they connect, pass through or pass by more than two consecutive storeys, or the areas they connect, pass through or pass by include one or more patient care areas. The terms “connect”, “pass through” and “pass by” include the following situations:

• Where the exit provides access to the storey
• Where the exit passes through the storey but does not necessarily provide access to or egress for the storey

D1.3(b)(ii) allows an exemption for open spectator stands because of their open nature, which means that the build up of smoke is unlikely.

D1.3(b)(iii) does not apply to:

• a Class 9a building;
• a Class 9c building; or
• an open spectator stand.

D1.3(b)(iii) permits other Class 5–9 buildings to have non-fire-isolated exits provided they do not connect, pass through or pass by more than two consecutive storeys, plus an extra storey of any classification under specified conditions. The terms “connect”, “pass through” and “pass by” include the following situations:

D1.4 Exit travel distances

Class 2 and 3 buildings —

The entrance doorway of any sole-occupancy unit must be not more than—

6 m from an exit or from a point from which travel in different directions to 2 exits is available; or

20 m from a single exit serving the storey at the level of egress to a road or open space ; and

no point on the floor of a room which is not in a sole-occupancy unit must be more than 20 m from an exit or from a point at which travel in different directions to 2 exits is available.

Class 4 parts of a building — The entrance doorway to any Class 4 part of a building must be not more than 6 m from an exit or a point from which travel in different directions to 2 exits is available.

Class 5, 6, 7, 8 or 9 buildings — Subject to (d) , (e) and (f) —

no point on a floor must be more than 20 m from an exit , or a point from which travel in different directions to 2 exits is available, in which case the maximum distance to one of those exits must not exceed 40 m; and

in a Class 5 or 6 building, the distance to a single exit serving a storey at the level of access to a road or open space may be increased to 30 m.

Vic D1.4(d)

Class 9a buildings — In a patient care area in a Class 9a building—

no point on the floor must be more than 12 m from a point from which travel in different directions to 2 of the required exits is available; and

the maximum distance to one of those exits must not be more than 30 m from the starting point.

Open spectator stands — The distance of travel to an exit in a Class 9b building used as an open spectator stand must be not more than 60 m.

Assembly buildings — In a Class 9b building other than a school or early childhood centre , the distance to one of the exits may be 60 m if—

the path of travel from the room concerned to that exit is through another area which is a corridor, hallway, lobby, ramp or other circulation space; and

the room is smoke-separated from the circulation space by construction having an FRL of not less than 60/60/60 with every doorway in that construction protected by a tight fitting, self-closing , solid-core door not less than 35 mm thick; and

the maximum distance of travel does not exceed 40 m within the room and 20 m from the doorway to the room through the circulation space to the exit .

SA D1.4(g) and (h)

To maximise the safety of occupants by enabling them to be close enough to an exit to safely evacuate.

The D1.4 travel distances are based on an assumption of what is considered “reasonable” distances to be travelled by occupants in reaching an exit.

The travel distances specified in D1.4 are measured in accordance with D1.15 .

D1.4(a)(i)(A) and (B) require a shorter travel distance, to a single exit, for Class 2 and Class 3 buildings and Class 4 parts than is required for Class 5 to Class 9 buildings.

The distance occupants of sole-occupancy units in Class 2 and Class 3 buildings and Class 4 parts must travel to leave their unit is not part of the distance specified in D1.4 . Accordingly, the permitted distance of travel from the point at which the occupant leaves the unit must take account of the time needed for the occupant to reach that point from within the unit.

Distance of travel must factor in the time occupants need to wake up, become alert to their predicament, and exit in a state of confusion.

This process of becoming alert will inevitably require more time to exit. Therefore the distance of travel to an exit should be shorter.

Figure D1.4(1) illustrates various methods of complying with D1.4 for Class 2 and Class 3 buildings.

D1.4(c)(i) sets out the maximum travel distance in Class 5–9 buildings. This includes Class 9c buildings, but excludes Class 9a buildings, which must comply with D1.4(d) . (See comments on D1.4(d) for the reason Class 9a buildings are treated differently). The additional travel distance allowed in Class 9c buildings recognises the effectiveness of sprinkler systems that must be installed in these buildings.

The distances specified allow people to evacuate in a reasonable time, assuming that they are not asleep.

In case a fire blocks a path of travel, D1.4(c)(i) requires that alternative routes must be available within 20 metres of the starting point, unless it is possible to reach a single exit within 20 m.

The conditional reference in D1.4(c) to sub-clauses (d) , (e) and (f) refers to special provisions for particular types of building.

Figure D1.4(2) illustrates various methods of complying with D1.4 for Class 5 and Class 6 buildings.

D1.4(c)(ii) provides a concession for Class 5 and Class 6 buildings served by a single exit opening onto a road or open space. The concession only applies to the storey at the level of access to a road or open space.

D1.4(c)(ii) uses the phrase "at the level of access to a road or open space". The term "level" does not require the storey to be physically level or flush with the road or open space to obtain the concession, but simply requires that the storey is at a level from which occupants finally leave the building to reach a road or open space. The concession allows a greater travel distance of 30 m in lieu of 20 m to a single exit on the basis that occupants, including customers of a shop, are:

• generally aware of their surroundings in these types of buildings which are typically small shops or offices located at or near ground level;
• familiar with the location of the exit which is typically the main entrance to the shop or office; and
• familiar with the path of travel to reach the exit thereby allowing a prompt and direct egress from the space.

Small shops and offices at or near ground level also tend to have an open plan layout thereby allowing the exit to be easily sighted to permit safe and speedy egress where the space is located in close proximity to the external ground surface such as a road or open space.

The concession is applicable to a number of cases such as to any Class 5 and 6 parts of a building located in a storey at the level of access to a road or open space even though the storey may be served by more than one exit, subject to that part otherwise complying with D1.4(c)(ii) .

The concession is also available for Class 5 or 6 parts of a building containing other classifications (refer to A1.0(3)(a) ).

Patient care areas in Class 9a buildings can present particular problems in case of emergency egress. Such areas are likely to be occupied by people who are either fully or partly non-ambulatory, and in many cases confused or incapacitated by drugs and medical and post-operative conditions.

Accordingly, the allowable distance of travel to an exit in the patient care areas of a Class 9a building is less than for Class 5–8 buildings, non-patient care areas of Class 9a buildings, and Class 9b buildings.

D1.4(d) should be read in conjunction with C2.5 .

The construction of an open spectator stand is such that the build up of smoke is unlikely. Greater distances of travel to an exit are therefore permitted.

The concession available for assembly buildings is based on a specific level of fire and smoke separation being provided between the area being evacuated and the circulation space passed through to reach an exit.

To obtain the concession, D1.4(f)(iii) limits the distance of travel through the room being evacuated and across the circulation space outside that room to the exit.

D1.5 Distance between alternative exits

Exits that are required as alternative means of egress must be—

distributed as uniformly as practicable within or around the storey served and in positions where unobstructed access to at least 2 exits is readily available from all points on the floor including lift lobby areas; and

not less than 9 m apart; and

not more than—

in a Class 2 or 3 building — 45 m apart; or

in a Class 9a health-care building , if such required exit serves a patient care area — 45 m apart; or

in all other cases — 60 m apart; and

located so that alternative paths of travel do not converge such that they become less than 6 m apart.

To require that if an exit is inaccessible, access to any required alternative exit must be available within a reasonable distance.

Where a building requires multiple exits, the exits maximise the choices of a person evacuating, in case one exit becomes blocked.

D1.5(a) requires that where multiple exits exist, they must be distributed as uniformly as practicable to improve the level of safety when evacuating.

D1.5 specifies the minimum and maximum permitted distances between alternative exits (for example, two exits may be located next to one another, so long as they are not each other’s alternative in an emergency). Where scissor stairs are used, the shafts will be adjacent and separated by fire-resisting construction. However, the access doors to the alternative scissor stairs must comply with the minimum separation distance.

The minimum distance minimises the risk of fire spreading to block the alternative exit.

The maximum distance between alternative exits minimises the need to travel too far to reach an exit.

If alternative paths of travel converge too closely, both paths can be blocked by the same fire. The minimum distance between the paths of travel aims to negate this.

The minimum convergence distance only comes into operation when the paths of travel have already diverged to that distance. The paths can commence more closely together than the distance specified.

The travel distances specified in D1.5 are measured in accordance with D1.15 .

Figure D1.5(1) illustrates the method of measuring the maximum and minimum distances between exits.

Figure D1.5(2) illustrates the convergence prohibition on alternative paths of travel.

D1.6 Dimensions of exits and paths of travel to exits

In a required exit or path of travel to an exit —

the unobstructed height throughout must be not less than 2 m, except the unobstructed height of any doorway may be reduced to not less than 1980 mm; and

the unobstructed width of each exit or path of travel to an exit , except for doorways, must be not less than—

1.8 m in a passageway, corridor or ramp normally used for the transportation of patients in beds within a treatment area or ward area ; and

in a public corridor in a Class 9c aged care building , notwithstanding (c) and (d) —

1.8 m for the full width of the doorway, providing access into a sole-occupancy unit or communal bathroom; and

if the storey , mezzanine or open spectator stand accommodates more than 100 persons but not more than 200 persons, the aggregate unobstructed width, except for doorways, must be not less than—

1 m plus 250 mm for each 25 persons (or part) in excess of 100; or

if the storey , mezzanine or open spectator stand accommodates more than 200 persons, the aggregate unobstructed width, except for doorways, must be increased to—

2 m plus 500 mm for every 60 persons (or part) in excess of 200 persons if egress involves a change in floor level by a stairway or ramp with a gradient steeper than 1 in 12; or

in any other case, 2 m plus 500 mm for every 75 persons (or part) in excess of 200; and

in an open spectator stand which accommodates more than 2000 persons, the aggregate unobstructed width, except for doorways, must be increased to 17 m plus a width (in metres) equal to the number in excess of 2000 divided by 600; and

the unobstructed width of a doorway must be not less than—

in patient care areas through which patients would normally be transported in beds, if the doorway provides access to, or from, a corridor of width—

less than 2.2 m — 1200 mm; or

2.2 m or greater — 1070 mm,

and where the doorway is fitted with two leaves and one leaf is secured in the closed position in accordance with D2.21(b)(v) , the other leaf must permit an unobstructed opening not less than 800 mm wide; or

in patient care areas in a horizontal exit — 1250 mm; or

the unobstructed width of each exit provided to comply with (b) , (c) , (d) or (e) , minus 250 mm; or

Vic D1.6(f)(iv)

in a Class 9c building—

1070 mm where it opens from a public corridor to a sole-occupancy unit ; or

870 mm in other resident use areas ; or

800 mm in non- resident use areas , and where the doorway is fitted with two leaves and one leaf is secured in the closed position in accordance with D2.21(b)(v) , the other leaf must permit an unobstructed opening not less than 870 mm wide in resident use areas and 800 mm wide in non- resident use areas ; or

in any other case except where it opens to a sanitary compartment or bathroom — 750 mm wide; and

NSW D1.6(f)(vi)

the unobstructed width of a required exit must not diminish in the direction of travel to a road or open space , except where the width is increased in accordance with (b)(ii) or (f)(i) ; and

the required width of a stairway or ramp must—

be measured clear of all obstructions such as handrails, projecting parts of barriers and the like; and

extend without interruption, except for ceiling cornices, to a height not less than 2 m vertically above a line along the nosings of the treads or the floor surface of the ramp or landing; and

to determine the aggregate unobstructed width, the number of persons accommodated must be calculated according to D1.13 .

NSW D1.6(j)

To require exits and paths of travel to an exit to have dimensions to allow all occupants to evacuate safely within a reasonable time.

The D1.6(a) requirement for a minimum unobstructed height of two metres is considered to be a reasonable minimum for most people to safely walk through to gain egress.

D1.6(a) relates to the unobstructed height between a floor and:

• a ceiling; or
• a projection from a ceiling, such as a bulkhead, beam, cable tray, light fitting, pipe, sprinkler head or the like.

It should be noted that in addition to complying with D1.6 , exits and paths of travel to exits must comply with the minimum ceiling heights in F3.1 .

The reduction to a minimum of 1980 mm for doorways is to allow for a standard door frame.

The required exit and path of travel widths have been determined on the basis of an estimate of the width required to allow the safe exit of a given number of people expected in particular buildings.

D1.6(b) clarifies that the unobstructed width of any exit or path of travel to an exit is to not be less than the dimensions prescribed. These may then be added to achieve the aggregate width that is required.

D1.6(b)(iii) applies to Class 9c buildings. The additional width at doorways is to allow for greater manoeuvrability of beds, mobile baths, wheelchairs, walking frames and other equipment throughout the resident use areas.

Figure D1.6(1) illustrates two examples of how compliance with the corridor width provisions in a Class 9c building may be achieved.

Buildings, other than ward and treatment areas of a Class 9a building, accommodating up to 200 people (see D1.6(b) and (c) ) require minimum widths of:

• 1 metre for 0 to 100 people;
• 1.25 metres for 101 to 125 people;
• 1.5 metres for 126 to 150 people;
• 1.75 metres for 151 to 175 people; and
• 2 metres for 176 to 200 people.

See Figure D1.6(2) .

Above 200 people (see D1.6(d) ), there is a division between those buildings which have a change of floor level by way of stairways or ramps with a gradient greater than 1 in 12, and those which do not have such a change in floor level. The reason for this differentiation is that the change in floor level has the potential to create problems at exits, which could cause injuries and delays. The difference can be outlined as follows, and is illustrated in Figure D1.6(2) :

• 2.5 metres for 201 to 260 people;
• 3 metres for 261 to 320 people;
• 3.5 metres for 321 to 380 people;
• 2.5 metres for 201 to 275 people;
• 3 metres for 276 to 350 people;
• 3.5 metres for 351 to 425 people;

D1.6(c) , (d) and (e) refer to the required width of an exit or path of travel to an exit in terms of an “aggregate unobstructed width”. The exit or path may be less than the total required width (although each must achieve the minimum required width), but when the width of each exit or path is added together, the specified aggregate unobstructed width must be achieved.

The width of a doorway must be clear of all obstructions. This includes door handles or other attachments or any part of the door leaf and any part of the door frame, including the door stop.

D1.6(f)(i) and (ii) provide additional width for doorways in patient care areas to allow for the turning circle of beds, and other egress difficulties, such as those experienced by patients who require ambulatory assistance.

The width of a doorway comprising part of the exit or path of travel is permitted to be 250 mm less than the width of each exit. This allows for the installation of a standard door frame.

In the case of an exit comprising multiple doorways, this concession may be applied to each individual doorway.

Figure D1.6(3) shows alternative examples of the exit door width for a building requiring a total exit width of three metres.

D1.6(f)(iv) applies to Class 9c buildings. The additional width of doorways is to allow for greater manoeuvrability of beds, mobile baths, wheelchairs, walking frames and other equipment throughout resident use areas.

No doorway should be less than 750 mm in width, except doorways which open into toilets and bathrooms. However, minimum width requirements do apply to doorways which provide access to facilities required for people with disabilities (see D3.2 and F2.4 ).

D1.6(b)(ii) and (c)(ii) specify additional width requirements for the exit and path of travel to allow for the turning circle of beds.

D1.6(e) provides an exception for large open spectator stands to the exit and path of travel width required for other buildings.

Under D1.6(g) , the required unobstructed width of exit or path of travel must not be reduced in the direction of egress. This provision aims to avoid congestion in an exit or a path of travel to an exit.

A restaurant is located on the fifth floor of a building.

The restaurant may seat 250 people. This would require an aggregate exit width of 2.5 metres. One stairway, 2.5 metres in width, is provided to achieve the exit requirement.

The fourth floor of the same building may be used as an office, with 100 staff, requiring an aggregate exit width of only 1 metre.

The 2.5 metre wide stairway from the fifth floor cannot be reduced to 1 metre when it reaches the fourth floor. The stairway must retain its 2.5 metre width throughout its length.

The exit width is not required to increase to 3.5 metres below the 4th floor. The BCA makes the assumption that the occupants of both floors are unlikely to all be exiting through the same part of the stairway at the same time.

If the restaurant was below the office, the stairway could begin at 1 metre in width at the office, but would have to increase to 2.5 metres after it passed the restaurant.

Under D1.6(h)(i) , the required stairway width must be measured clear of obstructions, including handrails and projecting barriers.

A stairway has handrails along both sides and they are located within the width of the stairway (as opposed to along the top of a banister along the edge of the stairway).

In this case, the required stairway width must be measured between the handrails (presuming that there are no other obstructions intruding into the stairway).

Under D1.6(h)(ii) , the required width of a stairway must continue to a height of 2 metres above the stair. This measurement is consistent with other similar BCA requirements.

Figure D1.6(4) illustrates compliance with D1.6(h) .

D1.7 Travel via fire-isolated exits

A doorway from a room must not open directly into a stairway, passageway or ramp that is required to be fire-isolated unless it is from—

a public corridor , public lobby or the like; or

a sole-occupancy unit occupying all of a storey ; or

a sanitary compartment , airlock or the like.

Each fire-isolated stairway or fire-isolated ramp must provide independent egress from each storey served and discharge directly, or by way of its own fire-isolated passageway —

to a road or open space ; or

to a point—

in a storey or space, within the confines of the building, that is used only for pedestrian movement, car parking or the like and is open for at least 2 / 3 of its perimeter; and

from which an unimpeded path of travel, not further than 20 m, is available to a road or open space ; or

into a covered area that—

adjoins a road or open space ; and

is open for at least 1/3 of its perimeter; and

has an unobstructed clear height throughout, including the perimeter openings, of not less than 3 m; and

provides an unimpeded path of travel from the point of discharge to the road or open space of not more than 6 m.

Where a path of travel from the point of discharge of a fire-isolated exit necessitates passing within 6 m of any part of an external wall of the same building, measured horizontally at right angles to the path of travel, that part of the wall must have—

an FRL of not less than 60/60/60; and

any openings protected internally in accordance with C3.4 ,

for a distance of 3 m above or below, as appropriate, the level of the path of travel, or for the height of the wall, whichever is the lesser.

If more than 2 access doorways, not from a sanitary compartment or the like, open to a required fire-isolated exit in the same storey —

a smoke lobby in accordance with D2.6 must be provided; or

the exit must be pressurised in accordance with AS 1668.1 .

A ramp must be provided at any change in level less than 600 mm in a fire-isolated passageway in a Class 9 building.

To enable occupants to safely enter a fire-isolated exit which discharges to a safe location.

D1.7(a) requires that a doorway must not open into a fire-isolated exit unless it opens from a public area, a sole-occupancy unit which occupies a whole floor, or a toilet. This is to limit the number of entry points into a fire-isolated exit to retain its fire-resisting performance.

Note that D1.7(a)(i) refers to a “public corridor, public lobby, or the like”. A smoke lobby which serves at least two sole-occupancy units is a “public lobby”, and can open directly into a fire-isolated exit. Figure D1.7(1) illustrates permitted and prohibited entry into a fire-isolated passageway from sole-occupancy units in a shopping centre.

D1.7(b)(i) requires fire-isolated exits to discharge to roads or open spaces. However, there are some exemptions:

• D1.7(b)(ii) sets out the requirements for a fire-isolated exit to discharge into an area within a building (including the requirement that it be open for at least two thirds of its perimeter, to aid smoke ventilation); and
• D1.7(b)(iii) sets out the requirements for a fire-isolated exit to discharge into a covered area outside the building (including the requirement that it be open for at least one third of its perimeter, to aid smoke ventilation).

Figures D1.7(2) and (3) illustrate some of the options available by the use of D1.7 .

D1.7(c) sets out the FRL and opening protection requirements where the path of travel from the point of discharge of a fire-isolated exit to a road or open space necessitates passes within six metres of any part of the external wall of the building being evacuated. The provision only applies at the level of discharge. So if the exit discharges at ground level, any first storey wall or window would not need protection. The reason is that a fire on the first floor is unlikely to affect people exiting one storey below.

Figure D1.7(4) illustrates when walls and window openings require protection in accordance with D1.7(c) .

D1.7(d) requires the use of a smoke lobby or a pressurisation system to stop the entry of smoke into the fire-isolated exit, if more than two access doorways described in D1.7(a)(i) or (ii) are provided in the same storey. This provision must be read in conjunction with D1.7(a) , it does not over-ride it. See Figure D1.7(1) .

D1.7(e) requires a ramp where there is any change in level in a fire-isolated passageway in a Class 9 building and that change is less than 600 mm.

D1.8 External stairways or ramps in lieu of fire-isolated exits

An external stairway or ramp may serve as a required exit in lieu of a fire-isolated exit serving a storey below an effective height of 25 m, if the stairway or ramp is—

non-combustible throughout; and

protected in accordance with (c) if it is within 6 m of, and exposed to any part of the external wall of the building it serves.

For the purposes of this clause—

exposure under (a)(ii) , is measured in accordance with Clause 2.1 of Specification C1.1 , as if the exit was a building element and the external wall of the building was a fire-source feature to the exit , except that the FRL required in Clause 2.1(a)(i) must not be less than 60/60/60; and

the plane formed at the construction edge or perimeter of an unenclosed building or part such as an open-deck carpark , open spectator stand or the like, is deemed to be an external wall ; and

openings in an external wall and openings under (c) and (d) , are determined in accordance with C3.1 .

The protection referred to in (a)(ii) , must adequately protect occupants using the exit from exposure to a fire within the building, in accordance with one of the following methods:

The part of the external wall of the building to which the exit is exposed must have—

no openings less than 3 m from the exit (except a doorway serving the exit protected by a –/60/30 fire door in accordance with C3.8(a) ); and

any opening 3 m or more but less than 6 m from the exit , protected in accordance with C3.4 and if wall wetting sprinklers are used, they are located internally.

The exit must be protected from—

any part of the external wall of the building having an FRL of less than 60/60/60; and

any openings in the external wall , by the construction of a wall, roof, floor or other shielding element as appropriate in accordance with (d) .

The wall, roof, floor or other shielding element required by (c)(ii) must—

have an FRL of not less than 60/60/60; and

have no openings less than 3 m from the external wall of the building (except a doorway serving the exit protected by a –/60/30 fire door in accordance with C3.8(a) ); and

have any opening 3 m or more but less than 6 m from any part of the external wall of the building protected in accordance with C3.4 and if wall wetting sprinklers are used, they are located on the side exposed to the external wall .

To detail the circumstances in which an external stairway or ramp can be provided instead of a fire-isolated stairway or fire-isolated ramp.

Compliance with D1.8 for external stairway or ramp is only required where the external stairway or ramp is proposed as an alternative to a required fire-isolated stairway or ramp. In other words, if a fire-isolated stairway or ramp is not required by the BCA, compliance is not required with D1.8 .

The use of an external stairway or ramp is permitted instead of a fire-isolated stairway or ramp up to a height of 25 metres. The reason external stairways or ramps are not permitted above this height is because of:

• the risk that people would suffer vertigo above this level;
• the risk that weather conditions, particularly wind, may become more severe above this height; and
• the need to enable any person who gets into difficulties on the stairway to be rescued by way of fire brigade ladders or other rescue equipment, which generally do not reach above this height.

Fire protection from the external wall of the building near the external exit and any openings in that wall, is required under D1.8(a ) and (b) to ensure that an average person using the exit is afforded adequate protection from flames and radiant heat from a fire within the building.

D1.8(c) provides two separate methods of protecting the external exit from a fire from within the building:

• protect the external wall of the building and any openings in the wall, within the prescribed distances to the exit (see Figure D1.8(1) ); or
• protect the exit by shielding construction where the exit is within the prescribed distances to the building (see Figure D1.8(2) ).

D1.8(d) provides requirements for the shielding construction and protection of any openings in that construction.

D1.9 Travel by non-fire-isolated stairways or ramps

A non- fire-isolated stairway or non- fire-isolated ramp serving as a required exit must provide a continuous means of travel by its own flights and landings from every storey served to the level at which egress to a road or open space is provided.

In a Class 2, 3 or 4 building, the distance between the doorway of a room or sole-occupancy unit and the point of egress to a road or open space by way of a stairway or ramp that is not fire-isolated and is required to serve that room or sole-occupancy unit must not exceed—

30 m in a building of Type C construction; or

60 m in all other cases.

In a Class 5, 6, 7, 8 or 9 building, the distance from any point on a floor to a point of egress to a road or open space by way of a required non- fire-isolated stairway or non- fire-isolated ramp must not exceed 80 m.

In a Class 2, 3 or 9a building, a required non- fire-isolated stairway or non- fire-isolated ramp must discharge at a point not more than—

15 m from a doorway providing egress to a road or open space or from a fire-isolated passageway leading to a road or open space ; or

30 m from one of 2 such doorways or passageways if travel to each of them from the non- fire-isolated stairway or non- fire-isolated ramp is in opposite or approximately opposite directions.

In a Class 5 to 8 or 9b building, a required non- fire-isolated stairway or non- fire-isolated ramp must discharge at a point not more than—

20 m from a doorway providing egress to a road or open space or from a fire-isolated passageway leading to a road or open space ; or

40 m from one of 2 such doorways or passageways if travel to each of them from the non- fire-isolated stairway or non- fire-isolated ramp is in opposite or approximately opposite directions.

In a Class 2 or 3 building, if 2 or more exits are required and are provided by means of internal non- fire-isolated stairways or non- fire-isolated ramps each exit must—

provide separate egress to a road or open space ; and

be suitably smoke-separated from each other at the level of discharge.

To require that a person using a non-fire-isolated stairway or ramp be provided with a safe evacuation path.

D1.9(a) requires that occupants in a required non-fire-isolated stairway or ramp are able to continue all the way down to the level from which egress to a road or open space is available.

D1.9(a) refers to a continuous means of travel comprising flights of stairs and landings. It would generally not be acceptable for an entire or substantial proportion of a storey to be called a “landing”.

The first diagram in Figure D1.9(1) illustrates non-compliance with D1.9(a) because the stair does not provide a continuous path of travel to the level providing egress to a road or open space. The second diagram in Figure D1.9(1) illustrates a method of compliance with D1.9(a) .

The distances specified in D1.9 apply only to a required non-fire-isolated stairway or ramp.

Figure D1.9(2) illustrates the method of measuring a travel distance down a stairway.

D1.9(b) and (c) provide requirements for the overall travel distances permitted on non-fire-isolated stairways. Figure D1.9(3) illustrates compliance with D1.9(b) and (c) .

D1.9(d) and (e) provide requirements for the travel distance permitted from the base of the non-fire-isolated stairway to the discharge point (note that this distance is part of the distances required under D1.9(b) and (c) ). Figure D1.9(4) illustrates compliance with D1.9(d) and (e) .

D1.9(f) provides the additional requirements for Class 2 and Class 3 buildings which are required to have 2 or more exits.

Figure D1.9(5) illustrates one method of an exit system in a Class 5–9 building complying with Section D .

D1.10 Discharge from exits

An exit must not be blocked at the point of discharge and where necessary, suitable barriers must be provided to prevent vehicles from blocking the exit , or access to it.

If a required exit leads to an open space , the path of travel to the road must have an unobstructed width throughout of not less than—

the minimum width of the required exit ; or

whichever is the greater.

If an exit discharges to open space that is at a different level than the public road to which it is connected, the path of travel to the road must be by—

a ramp or other incline having a gradient not steeper than 1:8 at any part, or not steeper than 1:14 if required by the Deemed-to-Satisfy Provisions of Part D3 ; or

except if the exit is from a Class 9a building, a stairway complying with the Deemed-to-Satisfy Provisions of the BCA.

The discharge point of alternative exits must be located as far apart as practical.

In a Class 9b building which is an open spectator stand that accommodates more than 500 persons, a required stairway or required ramp must not discharge to the ground in front of the stand.

NSW D1.10(f)

In a Class 9b building containing an auditorium which accommodates more than 500 persons, not more than 2 / 3 of the required width of exits must be located in the main entrance foyer.

The number of persons accommodated must be calculated according to D1.13 .

To require the safe discharge from an exit to a road or open space.

D1.10(a) requires that an exit must not be blocked at the point of discharge.

Barriers (such as bollards) must be installed, if they are necessary to prevent vehicles blocking access to, or discharge from, an exit.

If an exit discharges to an open space, D1.10(b) and (c) require that a safe means of travel be provided from the open space to a road. This means that the following criteria must be satisfied:

• D1.10(b) —to maximise the safety of people moving towards a road during an evacuation, the width of the path of travel from the open space to the road must be at least that required for the exit (and in no case less than one metre).
• D1.10(c) —to minimise the risk from falling or tripping, any stairways or ramps must comply with the rest of the BCA (eg construction of treads, landings etc). This may include the provision of ramps suitable for people with disabilities.

The link between the road and open space must be open to the sky for its length.

D1.10(d) requires that the discharge points of alternative exits be as far apart as possible, so that if the discharge from one of them is blocked, the other will still operate satisfactorily.

D1.10(e) requires that exits from an open spectator stand not discharge to the ground in front of the stand. There may be a large number of people viewing the event from the front of the stand, and they may obstruct the path of those evacuating.

There is also a risk that the front of the stand could be subject to severe heat radiation. Also the only egress to the road from the ground in front of the stand may be through the stand.

Under D1.10(f) , only two thirds of the required width of exits from an auditorium, such as a theatre or hall, are to discharge into an entrance foyer where the auditorium can accommodate more than 500 people. This restriction applies because there may be a large number of people in the foyer, possibly waiting for the next show, or to gain access to another auditorium. These people would obstruct the path of the people evacuating.

D1.11 Horizontal exits

horizontal exits must not be counted as required exits —

between sole-occupancy units ; or

in a Class 9b building used as an early childhood centre , primary or secondary school .

In a Class 9a health-care building or Class 9c building, horizontal exits may be counted as required exits if the path of travel from a fire compartment leads by one or more horizontal exits directly into another fire compartment which has at least one required exit which is not a horizontal exit .

In cases other than in (b) , horizontal exits must not comprise more than half of the required exits from any part of a storey divided by a fire wall .

Horizontal exits must have a clear area on the side of the fire wall to which occupants are evacuating, to accommodate the total number of persons (calculated under D1.13 ) served by the horizontal exit of not less than—

2.5 m 2 per patient/resident in a Class 9a health-care building or Class 9c aged care building ; and

0.5 m 2 per person in any other case.

Where a fire compartment is provided with only two exits , and one of those exits is a horizontal exit , the clear area required by (d) is to be of a size that accommodates all the occupants from the fire compartment being evacuated.

The clear area required by (d) must be connected to the horizontal exit by an unobstructed path that has at least the dimensions required for the horizontal exit and may include the area of the unobstructed path.

To detail how the installation of horizontal exits in a building is permitted as an alternative to a conventional exit.

Originally, provision was made for horizontal exits between fire compartments because some occupants can have difficulty evacuating, particularly those confined to bed or that have a disability.

Subsequently, it was accepted that horizontal exits would be of value in other buildings, where they could overcome problems associated with large fire compartments, eg excessive distances to travel to exits.

The use of horizontal exits can overcome some of the difficulties outlined above, although they need to be used in conjunction with some other form of exit.

In an emergency, the Deemed-to-Satisfy Provisions require that occupants travel for limited distances before they reach a place of safety. A “place of safety”, in the case of horizontal exits, means the connecting fire compartment to which people will flee.

For a horizontal exit to comply with the Deemed-to-Satisfy Provisions of Section D , it must meet the following criteria:

• The distance of travel to the exit must not exceed that specified elsewhere in the BCA.
• The protection for a place of safety from its adjoining fire compartment is provided by a fire wall. The fire wall has a fire rating to match the classification of the fire compartments it divides and is expected to withstand a burnout of the respective areas. This provides an appropriate level of safety to people using the horizontal exit as they may have to remain in the place of safety for an extended period before evacuating via other exits.
• There must be another exit (other than a horizontal exit) from each place of safety entered by way of a horizontal exit. After escaping to the place of safety it should not be necessary to return to the area being evacuated to continue to evacuate from the building. D1.11(c) specifies a limit for the number of horizontal exits in a storey for buildings of other than Class 9a and Class 9c buildings.
• The place of safety must be large enough to temporarily accommodate the people from the area the horizontal exit is being provided for. It is important to note that if there is only one other exit in the fire compartment then the place of safety is to be large enough to accommodate all the occupants of the fire compartment. This is necessary because if the other exit is blocked then all the occupants will be required to exit through the horizontal exit. This is necessary until vertical evacuation is available. Since this accommodation is only for a short period, the areas specified generally only allow for people to stand. However, the larger areas specified for Class 9a health-care buildings and Class 9c buildings allows for patients or residents on beds to be wheeled through the horizontal exit to be accommodated in the place of safety.
• The path to the place of safety is to have dimensions equal to those of the horizontal exit to assist with the smooth evacuation of occupants.
• The swing of the horizontal exit door must be the same as other exit doors. This means that if the area is more than 200 m 2 (as specified in D2.20(b) ), the door is to swing in the direction of egress. If the FRL of the fire wall is three or four hours, two fire doors may be provided to achieve this FRL. In such cases, for both doors to swing in the one direction, a vestibule must be formed, as shown in Figure D1.11 .
• To make sure that evacuation is always possible, it is not permitted to have a horizontal exit to a separate sole-occupancy unit. This is because the owner or occupier of the other unit may lock the door for security reasons, barring entry (or exit) in an emergency.
• Where egress is required in either direction, two doors swinging in opposite directions or a 180° swinging door (complying with all BCA requirements including fire and smoke sealing capacities) may be used.

Horizontal exits may be useful as a means of evacuation from many health-care buildings. They can also be an advantage in large floor area buildings which need to be sub-divided by fire walls to reduce the size of the fire compartments. These fire walls can then be penetrated to create horizontal exits.

D1.12 Non-required stairways, ramps or escalators

An escalator, moving walkway or non- required non fire-isolated stairway or pedestrian ramp—

must not be used between storeys in—

a patient care area in a Class 9a health-care building ; or

a resident use area in a Class 9c building; and

may connect any number of storeys if it is—

in an open spectator stand or indoor sports stadium; or

in a carpark or an atrium ; or

outside a building; or

in a Class 5 or 6 building that is sprinklered throughout, where the escalator, walkway, stairway or ramp complies with Specification D1.12 ; and

except where permitted in (b) must not connect more than—

3 storeys if each of those storeys is provided with a sprinkler system (other than a FPAA101D system) complying with Specification E1.5 throughout; or

2 storeys , provided that in each case, those storeys must be consecutive, and one of those storeys is situated at a level at which there is direct egress to a road or open space ; and

except where permitted in (b) or (c) , must not connect, directly or indirectly, more than 2 storeys at any level in a Class 5, 6, 7, 8 or 9 building and those storeys must be consecutive.

To limit the spread of fire and smoke through unprotected openings for stairways, ramps, escalators and moving walkways.

D1.12 only applies to:

• escalators;
• moving walkways and travelators;
• non-required non-fire-isolated stairways; and
• non-required non-fire-isolated ramps.

Builders etc may choose to interconnect two or three storeys of a building with a non-required stairway, ramp or the like in accordance with D1.12 .

A two storey shop or suite of offices may be within a multi-storey building where all storeys are connected by a stairway which is both required and fire-isolated. This stairway may be external to the sole-occupancy unit which comprises the shop or office suite. For easy access within the sole-occupancy unit, another stairway may be located within the shop or office suite interconnecting the two storeys. That stairway is additional to the required stairway, and is not required to be fire-isolated.

D1.12(a) prohibits the use of a non-required non-fire-isolated stairway or ramp in a patient care area of a Class 9a building and a resident use area of a Class 9c building. The prohibition is because of the difficulties in evacuating bed-ridden, or otherwise mobility-impaired occupants. This prohibition applies to D1.12(d) , despite that provision’s general reference to Class 9 buildings.

D1.12(b) allows any number of storeys to be connected in certain buildings as follows:

• The open nature of the construction of an open spectator stand, sports stadium, carpark, atrium, and a stairway or ramp located outside a building is such that the build-up of smoke is unlikely. D1.12(b)(i) , (ii) and (iii) permit any number of interconnected floors in such cases.
• In a Class 5 or Class 6 building containing a sprinkler system, D1.12(b)(iv) allows connection of any number of storeys if the interconnecting stairway, ramp, or escalator and the like complies with Specification D1.12 .
• While D1.12(b)(ii) refers to atriums, there are additional requirements for atriums in Part G3 .

D1.12 restricts the number of storeys which can be interconnected by a non-required non-fire-isolated stairway, ramp or the like. This recognises that an unprotected opening for a stairway, ramp, escalator or the like can lead to the spread of fire or smoke from one floor to another.

The restriction applies if:

• D1.12(c)(i) —a Class 2–9b building (excluding Class 9a) contains a sprinkler system, no more than three consecutive storeys can be linked, one of which storeys must directly egress to a road or open space. This recognises the effectiveness of a sprinkler system in controlling the spread of fire;
• D1.12(c)(ii) —the building is an unsprinklered Class 2 or Class 3 building, two consecutive storeys can be linked, one of which must directly egress to a road or open space. Part D1 does not generally apply to sole-occupancy units in Class 2 or Class 3 buildings, or Class 4 parts, and there is no restriction on an internal non-required non-fire-isolated stairway, ramp or the like linking two storeys in, for example, a two storey penthouse suite; or
• D1.12(d) —in a Class 5 or Class 6 building which does not qualify under D1.12(b)(iv) , and in Class 7–9b buildings (excluding a patient care area in a Class 9a, see D1.12(a) ), two consecutive storeys can be linked.

Neither storey is required to provide direct egress to a road or open space and there is no requirement for a sprinkler system as part of this provision. As the stairway or ramp is not required by the BCA for emergency evacuation purposes, this provision is in accord with the remainder of the BCA.

D1.13 Number of persons accommodated

For the purposes of the Deemed-to-Satisfy Provisions , the number of persons accommodated in a storey , room or mezzanine must be determined with consideration to the purpose for which it is used and the layout of the floor area by—

calculating the sum of the numbers obtained by dividing the floor area of each part of the storey by the number of square metres per person listed in Table D1.13 according to the use of that part, excluding spaces set aside for—

lifts, stairways, ramps and escalators, corridors, hallways, lobbies and the like; and

service ducts and the like, sanitary compartments or other ancillary uses; or

reference to the seating capacity in an assembly building or room; or

any other suitable means of assessing its capacity.

NSW Table D1.13

Note to Table D1.13 : Bar standing is the area used by standing patrons and extends not less than 1.5 m wide from the outside edge of the bar top for the length of the serving area of the bar.

To establish a methodology for calculating Deemed-to-Satisfy building populations which are deemed acceptable for use in the design and checking of applications when more accurate figures are not available.

D1.13 and Table D1.13 are used to calculate the anticipated number of people in particular types of building.

From these calculations, a number of BCA requirements can be determined within Sections D , E , F and J . The likely number of persons accommodated can affect determinations in relation to a number of matters in the BCA including; exit requirements, hearing augmentation, limitation of the use of stairway platform lifts, sanitary facilities, ceiling heights and the energy efficiency of mechanical ventilation systems.

D1.13 and Table D1.13 are only intended for the purposes of determining BCA requirements which depend on the number of occupants likely to occupy a building or storey. D1.13 and Table D1.13 are not intended to restrict the number of occupants using a building, or to enforce any building use or licensing requirements.

If more accurate information is available on the expected population of a building, it should be used in preference to Table D1.13 . This information may include:

• D1.13(b) —if the building is an assembly building or room, its seating capacity can be used; or
• D1.13(c) —where there is limited public access, a statement from the building owner as to the number of occupants who will use the building; or
• D1.13(c) —a study of the number of people using similar buildings. Such a study must include the number of people at various times. As an example, if the building is to be used as a shop, the figures must include the maximum numbers of people expected at peak times (such as before Christmas).

It would be appropriate to use an alternative means of assessing the number of occupants when:

• under D1.13 , a restaurant is deemed to accommodate one person for every square metre of floor area;
• if a specific restaurant has fixed tables, booths, dining alcoves and architectural features which occupy significant floor space, the actual number of patrons able to be accommodated may be much less than the number calculated using D1.13 ; and
• in such a case, it may be appropriate to use another method for calculating the number of people accommodated (such as counting the number of seats available for use by patrons), and hence calculating the total width of exits to be provided; however
• if such an approach is adopted, due allowance must be made for the employees, as well as the potential for alternative seating layouts which could increase the number of people in the restaurant.

The area per person contained in Table D1.13 for computer rooms applies to rooms housing computer infrastructure such as computer servers and where low occupant numbers occur. These circumstances are similar to those found in switch or transformer rooms. For computer training rooms and office areas containing computers, the area per person for an office or school classroom, as appropriate, should be used.

D1.14 Measurement of distances

The nearest part of an exit means in the case of—

a fire-isolated stairway , fire-isolated passageway , or fire-isolated ramp , the nearest part of the doorway providing access to them; and

a non- fire-isolated stairway , the nearest part of the nearest riser; and

a non- fire-isolated ramp , the nearest part of the junction of the floor of the ramp and the floor of the storey ; and

a doorway opening to a road or open space , the nearest part of the doorway; and

a horizontal exit , the nearest part of the doorway.

To identify the nearest part of an exit for the purposes of measuring travel distance.

D1.14 describes the point at which an exit has commenced with respect to both fire-isolated and non-fire-isolated exits.

Figures D1.15(1) and D1.15(2) illustrate methods of measuring the distance of travel specified in the BCA.

D1.15 Method of measurement

The following rules apply:

In the case of a room that is not a sole-occupancy unit in a Class 2 or 3 building or Class 4 part of a building, the distance includes the straight-line measurement from any point on the floor of the room to the nearest part of a doorway leading from it, together with the distance from that part of the doorway to the single required exit or point from which travel in different directions to 2 required exits is available.

Subject to (d) , the distance from the doorway of a sole-occupancy unit in a Class 2 or 3 building or a Class 4 part of a building is measured in a straight line to the nearest part of the required single exit or point from which travel in different directions to 2 required exits is available.

Subject to (d) , the distance between exits is measured in a straight line between the nearest parts of those exits .

Only the shortest distance is taken along a corridor, hallway, external balcony or other path of travel that curves or changes direction.

If more than one corridor, hallway, or other internal path of travel connects required exits , for the purposes of D1.5(c) the measurement is along the path of travel through the point at which travel in different directions to those exits is available, as determined in accordance with D1.4 .

If a wall (including a demountable internal wall ) that does not bound—

a corridor, hallway or the like,

causes a change of direction in proceeding to a required exit , the distance is measured along the path of travel past that wall.

If permanent fixed seating is provided, the distance is measured along the path of travel between the rows of seats.

In the case of a non- fire-isolated stairway or non- fire-isolated ramp , the distance is measured along a line connecting the nosings of the treads, or along the slope of the ramp, together with the distance connecting those lines across any intermediate landings.

To specify the method of measuring the distance of travel to an exit in various situations.

The distance of travel to an exit is measured by determining the path a person would walk from the most remote area of the building to the nearest exit.

The maximum distance of travel between required alternative exits is measured by determining the path a person would travel along in a case where a fire blocks the path of travel to the nearest exit. The path of travel to the alternative exit includes passing through the point at which travel in different directions to those exits is available.

It is necessary to measure around any walls, or other built obstructions (including a wall, a demountable wall, and permanent fixed seating). See D1.15(f) and (g) .

Generally, furniture, cars in a carpark and some non-built or non-fixed obstructions are not taken into account in the calculation of travel distance. However, there may be occasions when such matters must be taken into account.

Figure D1.15(2) and D1.15(3)

Figure D1.15(2) illustrates, by example, the method of measuring the distance of travel for Class 2 and Class 3 buildings and Class 4 parts.

Figure D1.15(3) illustrates, by example, the method of measuring the distance of travel for Class 5–9 buildings.

D1.16 Plant rooms, lift machine rooms and electricity network substations: concession

A ladder may be used in lieu of a stairway to provide egress from—

a plant room with a floor area of not more than 100 m 2 ; or

all but one point of egress from a plant room, a lift machine room or a Class 8 electricity network substation with a floor area of not more than 200 m 2 .

A ladder permitted under (a) —

may form part of an exit provided that in the case of a fire-isolated stairway it is contained within the shaft ; or

may discharge within a storey in which case it must be considered as forming part of the path of travel; and

for a plant room or a Class 8 electricity network substation , must comply with AS 1657 ; and

for a lift machine room, where access is provided from within a machine room to a secondary floor, a fixed rung type ladder complying with AS 1657 may be used, provided that—

the height between the floors is not more than 2800 mm; and

the ladder is inclined at an angle to the horizontal not less than 65 degrees nor more than 75 degrees; and

the distance between the front face of the ladder and any adjacent obstruction is not less than—

960 mm, where the ladder is inclined 65 degrees to the horizontal; or

760 mm, where the ladder is inclined 75 degrees to the horizontal; or

a distance that is determined by interpolating the values in (aa) and (bb) , where the ladder is inclined at any angle between 65 degrees and 75 degrees to the horizontal; and

a clear space not less than 600 mm exists between the foot of the ladder and any equipment.

SA D1.16(c)

To provide concessions for small plant rooms, lift motor rooms and Class 8 electricity network substations.

Concessions (such as the use of a ladder in lieu of a stairway) are granted for small plant rooms, lift motor rooms and Class 8 electricity network substations for the following reasons:

• the usual occupants of a small plant room, lift motor room or Class 8 electricity network substation are trained personnel familiar with the room’s hazards and layout and are capable of negotiating the service ladders in a safe manner;
• it is reasonable to assume that if the plant or lift motor room is small, so also will be the number of people who will ever occupy it;
• the small size of the room means that there is not a significant distance to travel to gain egress; and
• in the larger rooms which qualify for this concession, and multiple exits are provided, only one needs to be a stair.

Figure D1.16 illustrates some possible methods of using the concessions contained in D1.16 .

D1.17 Access to lift pits

Access to lift pits must—

where the pit depth is not more than 3 m, be through the lowest landing doors; or

where the pit depth is more than 3 m, be provided through an access doorway complying with the following:

In lieu of D1.6 , the doorway must be level with the pit floor and not be less than 600 mm wide by 1980 mm high clear opening, which may be reduced to 1500 mm where it is necessary to comply with (ii) .

No part of the lift car or platform must encroach on the pit doorway entrance when the car is on a fully compressed buffer.

Access to the doorway must be by a stairway complying with AS 1657 .

In lieu of D2.21 , doors fitted to the doorway must be—

of the horizontal sliding or outwards opening hinged type; and

self-closing and self-locking from the outside; and

marked on the landing side with the letters not less than 35 mm high:

“DANGER LIFTWELL − ENTRY OF UNAUTHORIZED PERSONS PROHIBITED − KEEP CLEAR AT ALL TIMES”

ACT Appendix

D1.18 Egress from early childhood centres

Every part of a Class 9b early childhood centre must be wholly within a storey that provides direct egress to a road or open space .

The requirements of (a) do not apply in a building with a rise in storeys of not more than 2, where the Class 9b early childhood centre is the only use in that building.

Explanatory information:

D1.18(a) recognises the difficulties associated with evacuation of early childhood centres . Should an early childhood centre be proposed within a storey that does not meet the requirements of D1.18(a), a Performance Solution is to be used to demonstrate compliance with the relevant Performance Requirements .

46 CFR § 116.500 - Means of escape.

(a) Except as otherwise provided in this section, each space accessible to passengers or used by the crew on a regular basis, must have at least two means of escape , one of which must not be a watertight door.

(b) The two required means of escape must be widely separated and, if possible, at opposite ends or sides of the space to minimize the possibility of one incident blocking both escapes.

(c) Subject to the restrictions of this section, means of escape may include normal exits and emergency exits , passageways, stairways, ladders, deck scuttles, and windows.

(d) The number and dimensions of the means of escape from each space must be sufficient for rapid evacuation in an emergency for the number of persons served as determined using § 116.438(n)(2) of this part.

(e) The dimensions of a means of escape must be such as to allow easy movement of persons when wearing life jackets. There must be no protrusions in means of escape that could cause injury, ensnare clothing, or damage life jackets.

(f) The minimum clear opening of a door or passageway used as a means of escape must not be less than 810 millimeters (32 inches) in width, however, doors or passageways used solely by crew members must have a clear opening not less than 710 millimeters (28 inches). The sum of the width of all doors and passageways used as means of escape from a space must not be less than 8.4 millimeters (0.333 inches) multiplied by the number of passengers for which the space is designed.

(g) A dead end passageway, or the equivalent, of more than 6.1 meters (20 feet) in length is prohibited.

(h) The maximum allowable travel distance, measured as actual walking distance from the most remote point in a space to the nearest exit , must not be more than 46 meters (150 feet).

(i) Each door, hatch, or scuttle, used as a means of escape , must be capable of being opened by one person, from either side, in both light and dark conditions. The method of opening a means of escape must be obvious, rapid, and of adequate strength. Handles and securing devices must be permanently installed and not capable of being easily removed. With the exception of individual staterooms, a door, hatch or scuttle must open towards the expected direction of escape from the space served.

(j) A means of escape that is not readily apparent to a person from both inside and outside the space must be adequately marked in accordance with § 122.606 of this subchapter.

(k) A ladder leading to a deck scuttle may not be used as a means of escape except:

(1) On a vessel of not more than 19.8 meters (65 feet) in length , a vertical ladder and a deck scuttle may be used as not more than one of the means of escape from a passenger accommodation space; or

(2) As not more than one of the means of escape from any crew accommodation space or work space .

(l) Each ladder used as a means of escape must be mounted at least 180 millimeters (7 inches) from the nearest permanent object in back of the ladder. Rungs must be:

(1) At least 405 millimeters (16 inches) in width; and

(2) Not more than 305 millimeters (12 inches) apart, and uniformly spaced for the length of the ladder with at least 113 millimeters (4.5 inches) clearance above each rung.

(m) When a deck scuttle serves as a means of escape , it must not be less than 455 millimeters (18 inches) in diameter and must be fitted with a quick acting release and a holdback device to hold the scuttle in an open position.

(n) Footholds, handholds, ladders, and similar means provided to aid escape, must be suitable for use in emergency conditions, of rigid construction, and permanently fixed in position, unless they can be folded, yet brought into immediate service in an emergency.

(o) Vessels described by 46 CFR 114.110 (f) must ensure that the two means of escape required in paragraph (b) of this section are unobstructed and not located directly above, or dependent on, a berth.

(p) On a vessel of not more than 19.8 meters (65 feet) in length , a window or windshield of sufficient size and proper accessibility may be used as one of the required means of escape from an enclosed space , provided it:

(1) Does not lead directly overboard;

(2) Can be opened or is designed to be kicked or pushed out; and

(3) Is suitably marked.

(q) Only one means of escape is required from a space where:

(1) The space has a deck area less than 30 square meters (322 square feet);

(2) There is no stove, heater, or other source of fire in the space;

(3) The means of escape is located as far as possible from a machinery space or fuel tank; and

(4) If an accommodation space, the single means of escape does not include a deck scuttle or a ladder.

(r) Alternative means of escape from spaces may be provided if acceptable to the Commanding Officer, Marine Safety Center .

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Building Standards technical handbook 2017: non-domestic buildings

The Building Standards technical handbooks provide guidance on achieving the standards set in the Building (Scotland) Regulations 2004 and are available in two volumes, Domestic buildings and Non-domestic buildings. This publication is available in html and also in PDF format (in 'supporting documents' ).

This document is part of a collection

• Building standards

Mandatory Standard

2.9.0 introduction.

While the number of deaths from fires in non-domestic buildings is less than domestic buildings the potential for significant life loss and injuries is far greater. This is due to the large occupancy capacities that may be involved and the complexity of occupant behaviour including the potential for delay in occupant evacuation following the outbreak of fire.

Occupants in buildings do not normally perceive themselves to be at risk from fire and are not fully aware of the speed that fire can spread. The risk to occupants is greater if they are asleep during the outbreak of fire as their ability to detect a fire and to escape will be greatly impaired.

Everyone within a building should be provided with at least one means of escape from fire that offers a safe passage to a place of safety outside the building . This should allow for them to escape from the building before being affected by fire or smoke. In certain circumstances, for example, where the travel distance is excessive, a second means of escape should be provided. This will allow the occupants to turn away from the fire and make their escape in the other direction. There may be up to four stages in the process of escape:

escape from the room of fire origin or escape from the fire where only one direction is possible

escape from the compartment of fire origin or until the safety of a fire resisting wall is reached

escape from the floor of fire origin to protected zones and escape stairs , and

escape from the building to a place of safety at ground level.

Due to the special fire precautions within residential care buildings , hospitals and enclosed shopping centres, additional guidance is provided in the annexes. However it is important to remember that the guidance in the annexes is in addition and supplementary to the guidance to Standard 2.1 to 2.15. For additional guidance on:

residential care buildings , see annex 2.A

hospitals , see annex 2.B

enclosed shopping centres, see annex 2.C.

Conversions - in the case of conversions , as specified in regulation 4, the building as converted shall meet the requirement of this standard (regulation 12, schedule 6).

2.9.1 Escape principles

The occupants should be able to leave the building or part of the building in relative safety during the outbreak of a fire without assistance from the fire and rescue service.

Designers generally achieve this by providing independent routes of escape either directly to a place of safety , or through an adjacent compartment or protected zone .

The time available to leave a room or compartment of fire origin before being overcome by fire or smoke is dependant on a number of key factors:

the number and mobility of occupants in the compartment or room of fire origin

the containment measures of the room or compartment of fire origin

the geometry of the room or compartment

means of early warning of fire

the fire dynamics (e.g. the fire load and the rate of fire growth)

the distance to reach a place of safety, a protected zone or another compartment , and

the number and width of exits.

There are many options available to designers when considering escape from buildings to a place of safety . However these options can be subdivided into 3 broad categories:

direct escape

internal escape

external escape.

Direct escape means that occupants can escape from a building directly to a place of safety by way of a final exit door without using an internal or external escape route . Whilst direct escape to a place of safety is preferable, this is not always possible or convenient, for example, in hospitals or multi-storey buildings with many floors high above the ground.

Internal escape is perhaps the most common method of escape from buildings . Occupants escape from fire using enclosed corridors and stairs inside the building to reach a final exit door from the building , which leads to a place of safety .

External escape routes are wholly or partially open to the external air therefore the risk of smoke logging is reduced compared with enclosed escape routes inside the building . External escape routes include external escape stairs , access decks and flat roofs . In certain circumstances, an escape route from a building may be by way of a flat roof or an access deck .

2.9.2 Occupancy capacity

The use of a building and its occupancy capacity can vary considerably. It is necessary therefore to calculate the appropriate number of occupants in each space for normal circumstances.

The occupancy capacity can be estimated by assigning a floor area per occupant, this is called the occupancy load factor. The occupancy capacity of a room or space (without fixed seating) can then be obtained by dividing the area in square metres by the relevant occupancy load factor. While some buildings such as residential buildings are designed for a definitive number of occupants other occupancies such as in offices can vary.

The table below is based on the following characteristics of the occupancy:

assembly and entertainment buildings , which may have high occupancy density and large undivided floor areas

offices, where desks, cabinets and office machinery will be present

shops , where display shelves, counters and racks will be present

residential buildings , where the number of occupants is generally controlled by the number of beds available

factory and storage buildings , where the occupancy capacity is normally low and goods or machinery will be present.

The values in the table can be used as a guide to assess the occupancy capacity of a room. Where the occupancy load factors listed in the table below are not used, a written statement of the occupancy capacity should be submitted to the verifier who may wish to confirm the figures (e.g. occupancy capacity may be based on the number of available seats; the figure should include the number of spaces available for wheelchair users).

Table 2.10. Occupancy capacity in rooms and spaces without fixed seating

Additional information:

The occupancy capacity in enclosed shopping centres should be calculated in accordance with annex 2.C.

Shop sales area are classified as follows:

shop sales areas other than those listed in sub-clause 2(b) including supermarkets and department stores (all sales areas), shops for personal services such as hairdressing and shops for the delivery or uplift of goods for cleaning, repair or other treatment or for members of the general public themselves carrying out such cleaning, repair or other treatment

shop sales areas in shops trading predominately in furniture, floor coverings, cycles, perambulators, large domestic appliances or other bulky goods or trading on a wholesale self-selection basis.

The descriptions; arcade, hall, gallery and room used in the table do not indicate a particular design or configuration of building .

2.9.3 Travel distance

Travel distance is the term applied to the distance that occupants have to travel to a protected door and is measured along the actual route of escape from any point within a storey, including the distance across rooms .

The further occupants need to travel within a building to reach a protected door the greater the risk from the effects of fire. The travel distance should allow for the occupants to reach a protected door before being overcome by fire or smoke. This distance will depend on the nature of the fire and the characteristics of the occupants.

Occupants should be able to reach a protected door before there is a noticeable accumulation of smoke in the route of escape.

Therefore, to provide for safe evacuation of the occupants, it is necessary to have limitations on the distance occupants should have to travel to reach a protected door .

The limitations on travel distances reflect the different levels of protection that are necessary for the building occupants, based on the fire hazard and occupancy profile. The distances and available directions of travel, given in the following table and the guidance on travel distance, reflect this philosophy.

Table 2.11. Recommended travel distance (m)

Additional information :

For additional guidance on residential care buildings , see annex 2.A.

For additional guidance on hospitals , see annex 2.B.

For additional guidance on enclosed shopping centres, see annex 2.C.

If the building also contains a room or auditorium with provision for fixed seating, the more demanding travel distances should be used.

In a silage or grain store on a farm where the material is handled primarily by mechanical plant, the distance is 30m.

2.9.4 Measurement of travel distance

Travel distance is the distance measured along the actual route of escape from any point within a storey to the nearest protected door giving direct access to:

a place of safety , or

another compartment , or

a protected zone , or

an external escape stair , or

a flat roof or access deck , or

to a door in a sub-compartment wall as described in annex 2.A and annex 2.B.

In the case of a building which has only 1 direction of travel, the travel distance should be measured to a protected door giving access to an escape stair or a place of safety. In the case of a building or part of a building where there are at least 2 available directions of travel, the travel distance may be measured to any protected door.

Obstructions - where a floor is divided by fixed seating or other fixed obstructions, the travel distance should be measured by way of the shortest route along open seatways, gangways or circulation areas.

Internal stairs - where a measurement of travel distance includes an internal unenclosed escape stair , the travel distance should be measured along the pitch line from the centre of the nosing of the topmost tread to the lower landing, including the length of any intermediate landings.

2.9.5 Head room

An escape route and circulation area should have a clear headroom of at least 2m. In a doorway it may be reduced to not less than 1.9m.

2.9.6 Horizontal evacuation

In progressive horizontal evacuation, occupants within separate compartments remote from the fire may not need to evacuate the building . They may be able to remain within the building until the fire and rescue service has dealt with the fire or, if required, commence evacuation into an adjoining compartment or escape direct to the outside. The objective is to provide a place of relative safety within an adjoining compartment , from which further evacuation can be made if necessary but under less pressure of time.

Where the travel distance is measured to a protected door in a compartment wall :

there should be no fire shutter in that compartment wall , and

if the compartment does not contain either a final exit or direct access to a protected zone , then each of the adjoining compartments , should have at least 1 other escape route , which is not through a further compartment , and

the area of the adjoining compartment is:

at least the sum, in m 2 ; of the occupancy capacities of both compartments multiplied by 0.3, or

the escape route width available from the adjoining compartment is sufficient for the sum of the occupancy capacities of both compartments .

A fire in any one compartment should not prevent the occupants of any other compartment area from reaching a final exit.

See annex 2.A for additional guidance on residential care buildings and annex 2.B for hospitals .

2.9.7 Number of exits

To assess the numbers of exits required from the storey , the occupancy of the whole storey must be assessed. There is no need however to include adjoining parts of the building where the adjoining part does not communicate with the part under consideration.

The evacuation time from a room or storey is controlled by the number of exits and the time taken for occupants to pass through the exits. The fewer and narrower the exit the longer it can take for occupants to leave a room or storey, this is liable to cause irritation among those waiting, which in an emergency may lead to panic and crushing. Exits must therefore be numerous and wide enough to discharge the occupants before such conditions occur.

The number of escape routes from a room or storey exits relates to:

the use and occupancy profile within the building

the occupancy capacity

the height of a storey above the ground or the depth below ground, and

the travel distance involved.

To provide the occupants with the opportunity to move away from the effects of fire and smoke, on each storey of a building there should be sufficient exits to one or more of the following:

an escape stair

another compartment

directly to a place of safety .

In hospitals, the number of storey exits increase in proportion to the number of patient beds (see annex 2.B).

Room exits - it is important to realise that evacuating occupants from a building is dependant not only on the time it takes to reach an exit but also on the number that can be discharged through an exit in a given time. The tables below state the minimum number of exits that should be considered for a room depending on its occupancy capacity. For the purposes of this guidance, reference to a room shall include reference to a gallery , catwalk or openwork floor.

Table 2.12. Minimum number of room exits

The table below states the minimum number of exits that should be provided for a storey related to its occupancy capacity.

Table 2.13. Minimum number of storey exits

At least 2 storey exits should be provided from:

any storey at a height of more than 7.5m

any storey in a residential care building or hospital

a basement storey at a depth of more than 4.5m; or a basement storey which is intended to be used by members of the general public (other than a basement storey providing access only to sanitary accommodation ).

Single escape stair - it is possible to design a building with part of the upper storey at a height of not more than 7.5m to have only one escape route where the remainder of the storey has two escape routes . In cases where escape is by way of a single escape stair , access to the escape stair should be by way of a protected lobby .

Room exits to storey exits - where a room is located on a storey , which, due to the occupancy capacity, height of the storey or travel distance, is recommended to have 2 or more storey exits , the escape routes from the room exits to the storey exits should be designed as follows:

where only 1 room exit is provided, the escape route from the room should lead to 2 independent storey exits. However this need not be provided to:

any room or space inside a protected zone enclosing an escape stair (see clause 2.9.24), or

any room on a storey at a height of not more than 7.5m where the escape route provides access to a place of safety or to another compartment and the travel distance is designed in accordance with the guidance in clause 2.9.3 for one direction of travel.

where the occupancy capacity of a room is not more than 100, the room exits may give access to the same space provided the guidance for alternative directions of escape has been followed.

where the occupancy capacity of a room is more than 100, the room exits may also give access to the same space provided:

the guidance for alternative directions of escape has been followed, and

both escape routes are separated in the adjoining space by construction including a self-closing fire door , with a short fire resistance duration.

2.9.8 Escape route widths

To assist in the movement of occupants and reduce anxiety during an evacuation, escape routes should be wide enough to allow occupants to escape safely. The following recommendations for the width of escape routes are based on the speed and number of occupants that can move along an escape route together.

The aggregate unobstructed width in mm of all escape routes from a room, or storey, should be at least 5.3 x the occupancy capacity of the room or storey.

When a room or storey requires 2 or more escape routes , consideration should be given to the impact of one of the exits being affected by fire. The remaining exits, should be wide enough to allow all occupants sufficient time to leave the room or storey safely. Under these circumstances, when calculating the width of exits , the largest exits should be discounted. The aggregate width of the remaining exits need to be capable of accommodating the total number of occupants of the room or storey .

The guidance on the width of exits assumes a unit width of 530mm per person and a rate of discharge of 40 persons per minute. In theory a corridor 530mm wide would be capable of discharging 100 occupants in 2.5 minutes, but such a width would not allow occupants to move around freely and without difficulty, to the best of their ability. The unobstructed width of each individual escape route should be at least 1200mm to assist occupants with sensory, cognitive and/or mobility impairments. However where only stepped access is provided to a part of the building , the escape route may be reduced as follows:

in buildings with not more than 225 occupants the minimum width may be reduced to 1100mm

in buildings with not more than 100 occupants the minimum width may be reduced to 1000mm.

Doorways can reduce the width of escape routes by 150mm. This nominal reduction allows for the construction of door frames, however:

where the number of occupants using the escape route is not more than 225, the clear opening width of the doorway should be at least 850mm

where the number of occupants using the escape route is not more than 100, the clear opening width of the doorway should be at least 800mm.

The clear opening width at doorways is measured in accordance with the diagram below:

Figure 2.7. Clear opening width at doorways

Constancy of width - an escape route should not narrow in the direction of escape. However an escape route may pass through a wider circulation area leading to a narrower circulation area provided the latter is of a width at least that recommended for the escape route . Width of escape stairs is covered in clause 2.9.31.

The strict application of the above guidance may not be appropriate in all cases as follows:

a hospital, where staff will move bed patients into a safe area within the building , or

enclosed shopping centres where the mall is regarded as a place of relative safety.

More detailed guidance for hospitals is provided in annex 2.B and for enclosed shopping centres in annex 2.C.

2.9.9 Direction of escape

Everyone within a room when confronted by an outbreak of fire should be provided with at least one means of escape that offers safe passage to an exit from that room.

A layout, which only follows the recommendations for travel distance and number of storey exits, may still result in an undesirable layout. For example if two exits are placed close together it may make it impossible for all occupants to reach either exit if the fire is close to the exits. It is essential therefore, that where more than one exit is provided they are located so that at least one exit is available.

In many cases, there will not be an alternative at the beginning of the route. For example, there may be only one exit from a room to a corridor, from which point escape is possible in two directions. This is acceptable provided the distance the occupants have to travel, to the point where they can diverge in two or more directions, follows the relevant guidance in clause 2.9.3 for one direction of travel, and the overall route to a protected zone or place of safety follows the recommendations for more than one direction of travel.

Where more than one room exit is provided, the directions of travel from any point within the room should:

diverge at an angle of at least 45°, or

be combined for a distance not more than that allowed for one direction of travel and then diverge to two exits at an angle of at least 45° plus 2½° for every metre travelled in one direction (see table to clause 2.9.3).

To reduce the risk of 2 room exits becoming impassable due to fire or smoke in the early stages of fire growth, the distance between the exits from the room should be more than twice the distance travelled in one direction.

2.9.10 Escape from inner room

Occupants within an inner room could become trapped where there is an outbreak of fire in the adjoining access room. Therefore, escape should only be by way of one other room, and the inner room should:

not be used as sleeping accommodation

have an escape route that does not pass through more than one access room

the access room should be fitted with a suitable automatic fire detection and alarm system to warn the occupants of the inner room of an out break of fire

the access room should not be a place of special fire risk .

2.9.11 Fixed obstructions/furnishings

Storage areas of buildings with fixed obstructions should provide unobstructed access to an exit. Access to an exit in such buildings may be by way of a gangway. The width of gangways between fixed obstructions (including fixed racking or shelving and high-bay storage) should be at least 530mm. Due to the low occupancy and limited occupation in a building for the bulk storage of spirituous liquor, the width may be reduced to at least 400mm.

Fixed seating or furnishings - in a building , or part of a building , with fixed seating or fixed seating and fixed tables or other floor fixtures, there should be access to an exit by way of a gangway or a seatway, or a seatway directly to an exit; or a circulation area in accordance with the table and diagram below and:

in the case of an auditorium that has more than 1 exit, at least 1 exit should be provided at least two-thirds of the distance from any stage, screen or performing area towards the back of the room, and

a gangway or exit door should be provided at each end of a row of more than 12 fixed seats, and

in the case of shops where the room, or part of the room, has an occupancy capacity of more than 100, the minimum width of a circulation area should be designed as if the circulation area were an escape route , or

in the case of buildings to which the Safety of Sports Grounds Act 1975 applies, it is appropriate to use the Guide to safety at sports grounds http://www.culture.gov.uk .

Figure 2.8. Plan of room with provision for fixed seating

Figure 2.9. Method of measuring seatway widths

Table 2.14. Minimum width of gangways & seats in a room with fixed seating

May be reduced to 900mm where the occupancy capacity of the room is not more than 60.

The travel distance should be measured by way of the shortest route along open seatways, gangways or circulation areas.

2.9.12 Escape routes in residential buildings

In residential buildings occupants are particularly vulnerable to fire when asleep. Occupants may also be unfamiliar with their accommodation and escape routes . Those occupants on the fire floor should be provided with the opportunity to reach a protected zone (or other escape route ) in relative safety and as quickly as possible, therefore, the movement of fire and smoke to the escape route should be inhibited.

In a residential building , where any corridor escape route serves sleeping accommodation it should be constructed of walls providing a short fire resistance duration and any door in the wall should be a suitable self-closing fire door with a short fire resistance duration. However the fire door to the cleaners cupboard need not be self closing provided it is lockable.

This guidance may need to be adapted in a residential building used as a place of lawful detention due to the unique operational factors.

For additional guidance on residential care buildings and hospitals see annex 2A and 2B.

2.9.13 Fire and smoke control in corridors

The first hazard to occupants beyond the room of fire origin is likely to be from the products of combustion. Any migration of fire and smoke to an escape route may deter occupants from using it.

Every corridor, that is used as an escape route that exceeds the dimensions in the guidance below, should be:

subdivided with a wall or screen with a short fire resistance duration, or

protected by the installation of a smoke control system.

Where the corridor is subdivided by a wall or screen with a short fire resistance duration (insulation criteria need not be applied) any door in the wall or screen should be a self-closing fire door and:

where the corridor is a dead end more than 4.5m long and provides access to a point from which more than 1 direction of escape is possible, it should be divided at that point or points, as shown in the diagram below and

where the corridor provides at least 2 directions of escape and is more than 12m in length between the exits it serves, it should be divided in the middle third of the corridor. This does not mean that the corridor should be subdivided into 12m lengths.

Figure 2.10. Corridor division

Where a cavity extends across any of the self closing fire doors identified above, or above the walls described in clause 2.9.12 a cavity barrier with at least short fire resistance duration should be fitted above the sub-dividing wall and fire door to inhibit fire and smoke spread.

Smoke control systems - when a design incorporates a smoke control system in a building , other than a residential care building or hospital , it should employ smoke differentials in accordance with BS EN 12101: Part 6: 2005, but assuming a minimum pressure difference (over the wall being assessed) of 25 Pa based on a wind speed of 22m/sec. Mechanical smoke ventilation using pressure differentials may be used to inhibit smoke spread into escape routes by means of:

depressurisation systems, or

pressurisation systems.

The merits and limitations of each system should be assessed before deciding which system to choose.

A depressurisation system is based on the principle of extracting smoke to the outside air. This creates a negative pressure in the space relative to the adjacent spaces. Where a smoke ventilation depressurisation system is used, replacement air should be provided for the system to operate effectively. The volume of air and smoke removed should be replaced with the equivalent volume of replacement air at a sufficient rate in order to ensure a smoke flow out of the building . Reducing the rate of replacement air can result in the smoke ventilation system becoming less efficient whereas increasing replacement air and extraction at high velocities can produce air pressure conditions which make doors difficult to open. The system should be balanced to ensure that the forces required to open doors are not greater than those specified in Section 4 Safety.

A pressurisation system is based on the principle of forcing air into the escape route which helps to keep smoke out. Forced air can be used to maintain a positive pressure in the escape route which produces an air flow through gaps around doors preventing the smoke from entering. The system design should take account of likely pressure reduction when occupants open doors to escape or when fire-fighters open doors to access the fire. The system should be balanced to ensure that the forces required to open doors are not greater than those specified in Section 4 Safety.

2.9.14 Openings in floors

In the event of a fire, there is always a risk that an opening in a floor could result in a proportion of fire or smoke and toxic fumes arising from a fire flowing up through the opening leading to a build-up of smoke on the upper storeys . This can pose a threat to life safety, particularly when the occupants are unfamiliar with the building . Smoke and flames rising through such an opening in a floor may impede evacuees from leaving the building . It is important when such a design is considered that it does not impair the ability of the occupants to escape. Occupants should be able to move directly away from the opening or continue their evacuation at a safe distance away from the edge of the opening.

Escape routes should not be compromised by openings between floors, such as at an escalator and fire safety measures are necessary to compensate for this increased level of hazard; the diagram below explains this principle.

In a building where there is an opening in any floor, not being a compartment floor or separating floor , an escape route should not be within 4.5m of the openings unless:

the direction of travel is away from the opening, or

there is an alternative escape route , which does not pass within 4.5m of the opening, or

a wall or screen with a short fire resistance duration for integrity is provided between the opening and the route of escape.

Figure 2.11. Openings in floors

2.9.15 Obstacles

Time can be a critical factor in ensuring occupants can leave the building before being overcome by the effects of fire and smoke. It is important therefore that an escape route provides a clear unobstructed route that does not restrict the flow of occupants.

To ensure the safe and smooth movement of occupants and prevent unnecessary increase in anxiety during an evacuation the following should not be part of an escape route:

an escalator, or

a turnstile, other than a suitably designed and installed turnstile unit with an emergency break out facility enabling the entire unit to open in the direction of escape, or

any shutter; other than one which is installed for security purposes across a shop front and which does not close automatically in the event of fire, or

a manual sliding door, accessible to the public.

A fixed ladder may be used to escape from a plant room (not being a place of special fire risk ), which is unoccupied other than for maintenance purposes.

Revolving doors and automatic doors can obstruct the passage of persons escaping. However they may be installed in an escape route if designed and installed in accordance with BS 7036: 1996 and are either:

arranged to fail safely to outward opening from any position of opening, or

provided with a monitored fail-safe system for opening the door from any position in the event of mains supply failure and also in the event of failure of the opening sensing device, and

opens automatically from any position in the event of actuation of any fire alarm in the fire alarm zone within which the door is situated.

2.9.16 Direction of door openings

Doors across an escape route can slow the flow of occupants and may lead to crowding. To ensure that doors on an escape route do not unduly delay escape they should open in the direction of escape. However doors across an escape route may open against the direction of escape where the occupancy capacity in the building , or part of the building is low as follows:

in a factory building or storage building where the occupancy capacity is not more than 10

in any other building where the occupancy capacity is not more than 60.

However if the door is an emergency door or a door serving a place of special fire risk , the side-hung door should open in the direction of escape regardless of occupancy levels.

2.9.17 Galleries

For the purposes of compliance with this standard a gallery is an integral part of the room into which it projects, and the occupants of a gallery would have the same awareness of an outbreak of fire in a room as the other occupants of that room. The limitations on the size of a gallery relative to the room into which it projects is to provide those occupants on the gallery with the same awareness of any outbreak of fire.

The safety of those using a gallery, relates to:

the use and occupancy characteristics within the room, and

the occupancy capacity, and

the travel distance, and

the number of escape routes .

A gallery should be open above and below to the room into which it projects and should not give access to any other room , other than a room with a means of escape independent of the gallery. The gallery may be wholly or partly enclosed below, where:

the floor of the gallery has a short fire resistance duration, and

at least 1 route of escape from the gallery is by way of a protected door .

2.9.18 Locks

Locks on exits doors or locks on doors across escape routes present difficulties when assessing the need for security against the need to allow safe egress from a building in the event of a fire. Security measures however should not compromise the ability of the occupants to escape from a building in an emergency.

In general, all doors on escape routes , should either not be fitted with locks, or they should only be fitted with fastenings that can be readily operated from the side approached by occupants making an escape. The operation of these locks should be readily apparent, without the use of a key or access control tokens and without having to manipulate more than one mechanism. This is not intended to prohibit the use of locks to secure a room , storey or building when unoccupied. This guidance may also need to be adapted in a building used as place of lawful detention due to the unique operational factors.

Where an exit door from a room, storey or a door across an escape route has to be secured against entry when the building or part of the building is occupied, it should only be fitted with a lock which is readily operated, without a key, from the side approached by occupants making their escape. Similarly, where a secure door is operated by a code, combination, swipe or proximity card, biometric data or similar means, it should also be capable of being overridden from the side approached by occupants making their escape (see also electrically operated locks).

Guidance on the types of hardware for timber fire and escape doors can be obtained from the Code of Practice, 'Hardware for Fire and Escape Doors' Issue 2, June 2006, published by the Door and Hardware Federation and the Guild of Architectural Ironmongers.

2.9.19 Mechanical or electro-mechanical panic exit locking devices

Different groups of users will have differing needs to enable them to escape quickly and easily from a building in the case of fire and this should be reflected in the type of lock chosen. For example, in buildings frequented by the general public it is important that the locks can be released by occupants who may be unfamiliar with the building and have received no training in the emergency procedures or the types of exit locks used in the building .

These locks are designed to operate on body pressure alone and require no knowledge of their operation to enable safe and effective evacuation of the building . In these cases, panic exit locks operated by a horizontal bar should be designed and installed in accordance with BS EN 1125: 1997.

2.9.20 Mechanical or electro-mechanical emergency exit locking devices

In buildings , or parts of buildings , that are not open to the general public, such as in offices or other working environments, the occupants should be awake and familiar with the building . When staff in such areas are trained both in the emergency procedures and in the use of the specific emergency devices fitted (see clause 2.0.8) then emergency exit devices to BS EN 179: 1997 can be installed. This type of locking device is released mechanically by a single action applied to the door lever handle or push pad to allow people familiar with the building to escape in an emergency.

Locking devices to BS EN 179: 1997 can also be used in buildings or areas used by the general public where the occupancy capacity is low. Therefore these devices should not be installed on any door accessible to the general public where the aggregate occupancy capacity of the rooms or storeys served by the door is more than 60 persons.

2.9.21 Electric locking devices that unlock on electrical power being withdrawn

Where there is a choice of escape routes and the doors on one direction of escape are fitted with devices giving mechanical escape which operate on body pressure alone to BS EN 1125: 1997 or by the use of a lever handle or push pad to BS EN 179: 1997, the alternative escape route could be fitted with fail unlocked, electric locking device, such as an electro-magnetic lock. These are devices that require electrical power to be withdrawn from them to unlock.

Fail unlocked, electric locks, may be installed on exit doors and doors across escape routes , which are inaccessible to the general public or, on any door accessible to the general public where the aggregate occupancy capacity of the rooms or storeys served by the door does not exceeds 60 persons.

Where the locks are intended to be used by occupants who are familiar with the building , staff in such areas, will need to be trained both in the emergency procedures and in the use of the specific locking devices fitted (see clause 2.0.8). Fail unlocked devices are not designed to be used by people in a panic.

Where installed in buildings that feature fail unlocked electric locks, they should operate in conjunction with a fire alarm system, the design of which should be determined by a fire risk assessment (see clause 2.0.8).

More detailed guidance on the type of fire alarm system most appropriate to the circumstances is contained in BS 5839: Part 1: 2002.

This type of ‘fail unlocked electric locking device’ should unlock instantly when electrical power is withdrawn and should unlock even when pressure is being applied to the escape door by occupants trying to escape at the time that electrical power is withdrawn.

‘Fail unlocked electric locks’ should not be installed on:

a protected door serving the only escape stair in the building (or the only escape stair serving part of the building ), or

a protected door serving a fire-fighting shaft, or

on any door which provides the only route of escape from the building or part of the building , or

on any door accessible to the general public where the aggregate occupancy capacity of the rooms or storeys served by the door exceeds 60 persons.

A delay in the opening of a door across an escape route, can lead to an increase in anxiety of occupants or possible panic. Therefore ‘fail unlocked electric locks’ should be programmed to fail to the unlocked position:

on operation of the fire alarm system

on loss of electrical power or system error

on activation of a manual door release unit (Type A) to BS EN 54: Part 11: 2001 they are connected to, positioned at the door on the side approached by occupants making their escape and where the door provides escape in either direction, a unit should be installed on both sides of the door.

Some electric locking devices fail locked on both sides of the door when electrical power is withdrawn and does not give mechanical escape by panic bar, handle or push pad. This type of electric locking should not be used on exit doors and doors across escape routes.

2.9.22 Auditoria

In a building containing an auditorium, a ventilation system should be provided above all stages so that in the event of fire the occupants can escape before being overcome by the effects of fire or smoke. The ventilation system should be designed in such a way that the direction of air movement in the event of fire is from the auditorium towards the stage. Ventilation may be provided by means of mechanical extract ventilation or by natural ventilation direct to the external air, additional guidance is provided in BS 5588: Part 6: 1991.

Escape from the part of the stage behind the safety curtain should be independent from that of the auditorium.

Ancillary fire hazard rooms in the stage area, such as scenery dock, workshop, stage basement, staff or other rooms associated with the stage should where reasonably practicable be enclosed by a construction with a short fire resistance duration.

In a building containing an auditorium having an occupancy capacity of more than 500, additional passive and active fire safety measures should be provided and any stage should be separated from the remainder of the building by walls of medium fire resistance duration.

However this does not apply to the following:

the proscenium opening, provided there is a safety curtain which conforms to BS 5588: Part 6: 1991, and

an open stage.

Any door openings in the proscenium wall other than the proscenium opening should be provided with protected lobbies with short fire resistance duration.

Where a stage is equipped with a safety curtain, a high level outlet over the stage and stage area should be provided to allow the safety curtain system to operate effectively by containing fire and smoke to the stage and to allow the escape of smoke and hot gases in the event of a fire on the stage.

Where a building has an open stage the smoke exhaust system should be sized to keep the auditorium relatively clear of smoke during the period of evacuation. Extract ventilation should preferably be taken from high level positions to assist in keeping the main auditorium clear of smoke. The size and performance of the smoke exhaust system will depend upon the size of the stage. Unless determined otherwise by a fire engineering calculation, natural exhaust ventilators over an open stage should have a combined total aerodynamic free area of at least 10% of the area of the stage.

Each case should be considered separately to ensure that smoke will not be transferred from one area to another, particularly where there are distinctly separate entertainment areas, which share common escape routes.

2.9.23 Protected lobbies

A protected lobby is located within a protected zone and is designed to inhibit the movement of fire and smoke from an adjoining room , storey or space into the escape stair or fire-fighting lobby. This is normally achieved by fire resisting construction together with at least 2 sets of self-closing fire doors between the fire and the escape stair or fire-fighting lobby.

Protected lobbies in non-domestic buildings are used:

to inhibit fire and smoke spread to escape stairs

to help occupants escape past the floor of fire origin

to provide a protected route of escape from the fire floor

to reduce the number or width of escape stairs in a building

to provide a relatively safe space for the fire and rescue services to set up a forward control point and to provide a bridgehead from which to commence operations (see Standard 2.14).

Buildings with 1 Escape route - occupants in buildings with only 1 escape route are at greater risk from being exposed to fire and smoke during their escape. Therefore, where a building has only 1 escape route by way of an escape stair , access to the escape stair should be by way of a protected lobby.

There is less risk in low rise non-residential buildings with low occupancy numbers, which have a fire warning and detection system installed as this should provide the occupants with sufficient time to escape. The occupants of such buildings should be awake, and have less distance to travel. Therefore, a protected lobby need not be provided where the building :

is a non-residential building with no more than 300 occupants, and

no storey is at a height of more than 7.5m, and

an automatic fire detection and alarm system is installed in the building as recommended in BS 5839: Part 1: 2002 to Category L1.

Occupants in tall buildings will take longer to escape from the building and are therefore at greater risk from being exposed to fire and smoke during evacuation. There is also the risk that more than 1 escape stair could be affected by fire or smoke. Therefore, in every building having a storey at a height of more than 18m above ground level, access to the protected zone containing the escape stair should be by way of a protected lobby . When a protected lobby is provided, the wall dividing a protected lobby from the remainder of the protected zone should have a short fire resistance duration for integrity only and any door in the wall should be a self-closing fire door with a short fire resistance duration. However see Standard 2.14 for fire and rescue service facilities.

2.9.24 Protected zones

A protected zone may or may not contain an escape stair and is intended to protect occupants during their evacuation to a place of safety .

Protected zones should be designed and constructed to withstand fire in an adjoining room or space. The protected zone should form a complete enclosure having at least a medium fire resistance duration. Every door in the wall of a protected zone should be a self-closing fire door with a medium fire resistance duration. However the floor of the lowest storey or an external wall (other than an external wall described in clause 2.9.36) need not be fire resistant.

Shared residential building - a protected zone in shared residential accommodation should have at least short fire resistance duration.

As a building becomes taller the distance to be travelled and time taken for the occupants to reach a place of safety increase. Therefore in buildings with any storey at a height of more than 18m, the enclosing structure of the protected zone should have long fire resistance duration on all storeys .

The accommodation within every protected zone should be limited to places where fire is unlikely to start. As the fire risk is considered low, a cleaners cupboards of not more than 3m 2 and toilets or washrooms may be sited in the protected zone .

In buildings with 2 or more protected zones, the occupants have an alternative route out of the building if one of the protected zones was affected by fire or smoke. A reception room, an office and a general store room , each of not more than 10m 2 may be located within the protected zone as they are of limited size and the potential fire load is low.

The wall separating the rooms/cupboards from the protected zone should have a short fire resistance duration and any door in the wall should be a self-closing fire door . A door to a cleaner’s cupboard need not be self-closing provided it is lockable. The walls/doors separating the toilets or washrooms from the protected zone need not have a fire resistance duration.

2.9.25 Enclosure of escape stairs

To protect occupants from fire and smoke when evacuating a building , an escape stair should be within a protected zone . However this is not necessary in the following situations:

an escape stair which connects 2 or more levels within a single-storey where the difference in level between the highest and lowest level is not more than 1.8m, or

an external escape stair with a total rise of not more than 1.6m, or

an external escape stair constructed in accordance with clause 2.9.37

an escape stair , from a gallery, catwalk (including lighting bridges), or openwork floor where they have:

an occupancy capacity of not more than 60, or

an occupancy capacity of more than 60 but not more than 100 and at least 1 route of escape is by way of a protected zone , an external escape stair or to another compartment . Where the occupancy capacity is more than 100 the escape stair should be enclosed within a protected zone .

2.9.26 Places of special fire risk

Due to a very high fire risk, with potential for rapid fire growth, a place of special fire risk should only be accessed from a protected zone by way of a protected lobby . This is to give additional protection to the protected route of escape.

2.9.27 Openings and service penetrations

Fire and smoke can easily pass through openings in protected routes of escape (see clause 2.0.6) which could prevent the occupants from escaping in the event of an outbreak of fire within the building . For this reason, the openings in protected routes of escape should be limited to openings such as smoke ventilation systems, chimneys , flue-pipes, self-closing fire doors and service openings, fire shutters or dampers.

It is important that ducted heating and ventilation systems including air conditioning systems, installed to maintain interior environment conditions, that serve the building should not transfer fire and smoke to or from; any compartment to any other compartment , escape route, common space, roof space or other concealed space. Therefore, in the event of an outbreak of fire, the system should automatically either shut off, or operate in smoke control mode. For more detailed guidance refer to BS 5588: Part 9: 1999.

In order to inhibit the spread of fire and smoke, the openings should be protected and fire stopped in accordance with the guidance to Standard 2.1.

2.9.28 Junctions

The junctions between protected routes of escape (see clause 2.0.6) and other parts of the building are vulnerable to fire and smoke. This is because fire and smoke can penetrate weaknesses at junctions which could compromise the means of escape. The designer should consider detailing at junctions to inhibit fire and smoke spread into the protected route of escape.

Where part of a building is a protected route of escape and forms a junction with any other part of the building including for example, an external wall , a separating wall , another compartment wall , or any other wall or screen forming a protected route of escape, the junction should maintain the fire resistance duration of the more demanding guidance.

In order to inhibit the spread of fire and smoke, junctions should be protected in accordance with clause 2.1.15 and for additional guidance on fire-stopping materials, see clause 2.1.14.

2.9.29 Fuel pipes

Pipes conveying fuel inside protected zones could accelerate fire growth and under certain conditions, create an explosive atmosphere within the building . Oil and liquefied petroleum gas can produce pool fires, i.e. a turbulent fire burning above a horizontal pool of vaporising hydrocarbon fuel. The pool fire can be either static e.g. where the pool is contained or a ‘running’ pool.

Fuel pipes carrying oil (other than a pipe conveying oil supplying a hydraulic lift) should be located outside protected zones . A pipe conveying oil supplying a hydraulic lift may be located inside a protected zone . Fuel pipes carrying natural gas or liquefied petroleum gas (including associated meters) may be located within a protected zone provided:

the installation is in accordance with the requirements of the Pipelines Safety Regulations 1996, SI 1996 No 825 and the Gas Safety (Installation and Use) Regulations 1998 SI 1998 No 2451, and

any pipe is constructed of screwed steel or welded steel construction , and

the pipe or pipes are contained within a service shaft with at least a medium fire resistance duration from the outside, and

the service shaft is ventilated at high and low level in accordance with BS 8313: 1997.

2.9.30 Temporary waiting spaces

The speed of evacuation of occupants with sensory, cognitive and/or mobility impairments can be much slower than other building users. Therefore, a space should be provided to allow them to wait temporarily, before completing their escape to a place of safety .

The safe evacuation of occupants with sensory, cognitive and/or mobility impairments is the responsibility of the employer or other person having control of the building and not that of the fire and rescue service. Therefore, occupants with sensory, cognitive and/or mobility impairments, should not be directed to remain in these spaces awaiting the arrival of the fire and rescue service. The employer or other responsible person should make the necessary arrangements for the safe evacuation of all occupants from the temporary waiting spaces.

The duty holder also has a duty under the Management of Health and Safety at Work Regulations 1999, to assess the risks to workers and any others, who may be affected by their work or business. Further requirements under the Fire (Scotland) Act 2005 and the Fire Safety (Scotland) Regulations 2006, in respect of fire safety risk assessment and further obligations in respect of fire safety measures must also be considered.

Temporary waiting spaces should have an unobstructed clear area capable of accommodating a wheelchair and measuring at least 700mm x 1200mm. They should be located in either:

a protected lobby , or

an adjacent compartment .

However it is not necessary to provide a temporary waiting space in a protected zone where the storey has level or ramped egress to a place of safety or on an external escape stair with a total rise of not more than 1.6m.

To assist the escape process and reduce the anxiety of occupants making use of the space, an emergency voice communication (EVC) system should also be provided in the designated temporary waiting space.

The EVC should follow the guidance in either:

BS 5839: Part 9: 2003 and consist of type B outstations and communicate with a master station located in the building control room (where provided) or adjacent to the fire alarm panels, or

in some buildings , it may be more appropriate to use alternative two way communication that can be readily operated by occupants in the temporary waiting space.

2.9.31 Escape stair widths

Every escape stair should be wide enough to accommodate the number of occupants needing to use it in an emergency and allow them to make their escape before being overcome by the effects of fire and smoke. This width will depend on the number of stairs provided and whether the escape strategy for the building (or part of the building ) is based on:

simultaneous evacuation, or

phased evacuation.

Minimum effective width - to help limit the potential for queuing at the storey exit which in an emergency may lead to panic and crushing, the effective width of an escape stair should be at least the width of any escape route giving access to it. Therefore the effective width of each escape stair should be at least 1200mm to assist occupants with sensory, cognitive and/or mobility impairments. However where the building has limited occupancy numbers the escape stair width may be reduced as follows:

1100mm where the number of occupants using the stair is not more than 225, and

1000mm where the number of occupants using the stair is not more than 100.

The effective width of an escape stair is measured between handrails and clear of obstructions.

Where the number of occupants using the escape stair is more than 225 then the formula for calculating the effective width of the stair should be used. The escape stair should not narrow in the direction of escape.

Appropriate capacity - to assist the verifier and designer establish the width of an escape stair , it is necessary to establish the number of escape stairs and the number of occupants who will access them on each storey . The effective width of escape stairs is based on the number of occupants who will use each escape stair and the resultant figure is known as the appropriate capacity (AC). The methodology for calculating the appropriate capacity must also take into account whether a building has been based on simultaneous or phased evacuation.

Simultaneous evaluation - in a building designed on the basis of simultaneous evacuation the escape stairs (in conjunction with the rest of the means of escape) should have the capacity to allow the occupants of all storeys to evacuate at the same time.

The appropriate capacity in relation to an escape stair at any storey above or below the adjacent ground is calculated by one of the following methods.

Where the escape stair serves only one storey, the appropriate capacity equals the occupancy capacity of the storey served by the escape stair (see diagram below). The appropriate capacity for the storey should then be used in the formula for calculating the effective width of the escape stair .

Figure 2.12. One storey example

In a building in which the escape stair serves more than 1 storey the appropriate capacity for each storey should be calculated and the total appropriate capacity for all the storeys served by the escape stair should then be used in the formula for calculating the effective width of the escape stair . A deduction of 20% from the appropriate capacity is allowed for the number of occupants who could be standing in the stair.

This method of calculating the escape stair width can be used to reduce the width of the stair as it rises up the building although this would not be a typical form of construction .

Figure 2.13. More than one storey example

Phased evacuation allows occupants most at risk to be evacuated first. This allows the designer to reduce the width of the escape stairs and minimises disruption in large buildings . Tall buildings take longer to evacuate and where the building is at a height of more than 25m it is beyond the reach capability at which Fire and Rescue service can effect external rescue. Therefore, when phased evacuation is adopted in buildings additional active and passive fire protection measures will be necessary.

As phased evacuation relies on some occupants remaining where they are until instructed to leave, it is only suitable for buildings where the occupants are awake and familiar with the building , for example, offices.

The occupants first evacuated are those on the storey of fire origin and those on the storey immediately above. If further evacuation is required this is done on the basis of the next two adjoining upper storeys to avoid congestion in the escape stairs . The remaining storeys would then be evacuated two storeys at a time however this would be dependent on the severity of the fire and any direction given by the fire and rescue service.

Because of the additional time it may take to evacuate a building or part of a building where the means of escape is based on vertical phased evacuation, the following fire safety measures should be provided:

installation of an automatic fire detection and alarm system to BS 5839: Part 1: 2002, Category L2, and

a voice alarm should be installed in accordance with BS 5839: Part 8: 2008. Such a system enables two or more stages of alarm to be given within a particular area, and

the escape stairs should be entered from a protected lobby , and

every storey should be a compartment storey , and

if the building has any storey at a height of more than 25m, every storey should be protected by an automatic life safety fire suppression system (see guidance to Standard 2.15), and

an internal speech communication system should be provided via a control point at the access level to allow the fire and rescue service to converse with a fire warden on every storey .

In a building where the stairs have been designed on the basis of vertically phased evacuation the appropriate capacity [AC] in relation to an escape stair at any storey above or below the adjacent ground is calculated by the following method and in accordance with the diagram below.

In a building , or part of a building , which is divided by one or more compartment floors , the appropriate capacity [AC] is equal to, the total occupancy capacity, less 20%, of each of the 2 adjacent upper storeys , served by the escape stair , or in the case of an escape stair serving a basement storey , the 2 adjacent basement storeys served by that escape stair , having in either case the greatest combined occupancy capacity.

Figure 2.14. Compartmented building example

Calculation of effective width - based on the above principles for simultaneous and phased evacuation, the effective width of every escape stair in mm can be calculated by the following formula:

EW = 5.3 x AC N − 1 EW = {5.3 x AC} over {N - 1}

EW is the effective width of an escape stair measured in mm between handrails and clear of obstructions

AC is the appropriate capacity, which in relation to an escape stair is the occupancy capacity of the storey served by the escape stair , less 20%

N - 1 is the number of escape stairs minus 1, unless it meets exception for protected lobbies above

A deduction of 20% from the appropriate capacity is made to allow for the number of occupants who could be standing in the stair.

Before using the formula it is necessary to consider the possibility that one stair may be affected by fire or smoke before all occupants have evacuated the building . For that reason one stair should be discounted for calculation purposes, unless a protected lobby is provided on every storey between each escape stair in a protected zone and any part of the building at any storey from which there is access to the escape stair.

If the escape stair contains any of the rooms listed in clause 2.9.24 the stair should be discounted from the stair width calculation.

Example 1 - simultaneous evacuation

What is the minimum effective width needed for escape stairs in an office building with 4 storeys and 2 escape stairs and which escape is based on simultaneous evacuation? For this example it is assumed that the occupants are distributed evenly across each storey, therefore the number of occupants will be split evenly to each escape stair .

There are 100 occupants on the top storey, 150 occupants on the 2nd storey and 200 occupants on the 1st storey. The escape routes on the ground storey do not communicate with the escape stairs.

It is assumed that the buildings do not have any protected lobbies, therefore the effective width equals:

AC is the appropriate capacity and is the sum of the occupancy capacity of the storeys served by the escape stair minus 20% for standing capacity in the stair:

Top storey = 100 x 0.8

2nd storey = 150 x 0.8

1st storey = 200 x 0.8

EW = 5.3 x 360 2 − 1 EW = {5.3 x 360} over {2 - 1}

= 1908 1 {1908} over {1}

The minimum width of each escape stair will be 1908mm.

Example 2 - simultaneous evacuation

What is the minimum effective width needed for escape stairs in an office building with 6 storeys and 3 escape stairs and which escape is based on simultaneous evacuation. For this example it is assumed that the occupants are distributed evenly across each storey, therefore the number of occupants will be split evenly to each escape stair .

Each storey has 300 occupants and the escape routes on the ground storey do not communicate with the escape stairs.

It assumed access to each protected zone containing the escape stair is by way of a protected lobby. Therefore, there is no need to deduct 1 stair from the calculations:

EW = 5.3 x AC N EW = {5.3 x AC} over {N}

AC is the appropriate capacity and is the sum of the occupancy capacity of the storeys served by the escape stair minus 20% for standing capacity in each of the stairs.

There are 5 storeys accessing the escape stair and each storey has 300 occupants the appropriate capacity is found by:

AC = 300 x 5 x 0.8

EW = 5.3 x 1200 3 EW = {5.3 x 360} over {2 - 1}

= 6360 3 {1908} over {1}

The minimum width of each escape stair will be 2120mm.

Example 3 - phased evacuation

What is the minimum effective width needed for escape stairs in an office building with 10 storeys and 3 escape stairs and which escape is based on phased evacuation. For this example it is assumed that every storey is a compartment storey and that the occupants are distributed evenly across each storey, therefore the number of occupants will be split evenly to each escape stair .

As escape is based on phased evacuation, access to each protected zone containing the escape stair should be by way of a protected lobby. Therefore, there is no need to deduct 1 stair from the calculations:

AC is the appropriate capacity of each of the 2 adjacent upper storeys , with the greater occupancy capacity, minus 20% for standing capacity in each of the stairs:

AC = (300 x 0.8) + (300 x 0.8)

EW = 5.3 x 480 3 EW = {5.3 x 360} over {2 - 1}

= 2544 3 {1908} over {1}

However as the effective width of each escape stair should be at least 1200mm all 3 stairs should be at least 1200mm wide.

Combined escape routes - where escape routes from a storey consist of a combination of escape stairs and other escape routes (see diagram below) the effective width of any escape stair from that storey should be designed to take into account that proportion of the number of occupants on that storey who may escape by way of the other escape routes .

The escape route should be sized to take account of all the occupants who will be escaping. Therefore, where the escape route from an escape stair is also the escape route from the ground storey and/or basement storey , the width of that escape route should be increased to take account of that proportion of the occupancy capacity from the ground storey and/or basement storey .

Figure 2.15. Combined escape example

2.9.32 Independence of escape stairs

Where there are alternative escape stairs from a storey , there is the risk that one of the escape stairs could be smoke logged preventing access through to the alternative escape stair . Where a room or storey needs two or more escape stairs , it should be possible to reach 1 alternative escape stair without passing through the other.

When the escape stairs are adjacent to one another, to reduce the likelihood of them becoming smoke logged at the same time, for example, where the protected zones enclosing escape stairs share a common wall, any access between them should be by way of a protected lobby .

2.9.33 Escape routes in a central core

To reduce risk of smoke spread to more than 1 escape stair , corridor or lobby, a building with more than 1 escape route contained in a central core, should be planned so that the exits from the storey are remote from one another, and so that no 2 exits are approached from the same lift hall, common lobby or undivided corridor or linked by any of these other than through self-closing fire doors .

Figure 2.16. Central core example

2.9.34 Escape stairs in basements

The limited natural ventilation available in a basement can lead to rapid heat and smoke build up. The heat and smoke generated can be forced up through any opening such as a door into a stairway. This means that fire-fighting in under-ventilated compartments must be approached with caution before opening the door to the basement storey .

There is also a risk that disoriented occupants could continue their escape to the basement storey instead of escaping through the ground storey .

In order to minimise these risks, a wall or screen (including a self-closing fire door ) with a medium fire resistance duration should be provided between the ground storey of the protected zone and the basement storey .

2.9.35 Construction of escape stairs

In buildings of more than 1 storey where the means of escape is via an escape stair , this will also be the route from which the fire and rescue services will fight the fire and effect rescue. The possibility that the escape stair may be affected by fire breaking out or being deliberately set in the stairway has to be considered. Consequently the escape stair should be provided with additional protection.

Therefore, every part of an escape stair (including landings) and the floor of a protected zone or protected lobby , should be constructed of non-combustible material. However this does not apply to:

an escape stair in shared residential accommodation

any handrail, balustrade or protective barrier on an escape stair

an escape stair which connects 2 or more levels within a single-storey where the difference in height between the highest and lowest level is not more than 1.8m

an escape stair from a gallery, catwalk or openwork floor constructed in accordance with the guidance in clause 2.9.25

a floor finish (e.g. laminate flooring) applied to the escape stair (including landings) or to the floor of a protected zone or protected lobby .

2.9.36 External walls adjacent to protected zones

If a protected zone has an external wall that projects beyond the face of a building or is set back in a recess, the protected zone may be vulnerable to fire following the break out of fire through an adjacent window, door or other opening. Radiated heat or flames from the fire may impede occupants using the protected zone to escape.

Therefore where any part of a protected zone is not more than 2m from, and makes an angle of not more than 135° with any part of an external wall of another part of the building , the escape stair should be protected against fire for a distance of 2m, by construction with a:

short fire resistance duration where every storey in the building is at a height of not more than 7.5m above the ground, or

medium fire resistance duration where any storey is at a height of more than 7.5m.

The designer can choose which wall should be fire resisting and may include fire resisting facades or other fixed glazing, or any other opening protected against fire. However it is not sufficient to use the final exit door as a barrier between the occupants escaping and the fire. In such cases the external wall adjoining the protected zone at the final exit should be protected against fire as described above.

2.9.37 External routes of escape

Escape routes will normally lead to the final exit door of the building , which leads to a safe place in the outside air from which occupants can freely disperse. An exit can also lead to an external escape stair, a flat roof or access deck giving access to a place of safety.

Protection of external route of escape - in some cases it may not be possible to freely disperse away from the building (e.g. where the final exit door discharges to an enclosed outdoor space). In such cases, where there is only 1 route of escape, the external wall of the building within 2m of the route of escape should have a short fire resistance duration for integrity up to 1.1m above the adjoining ground. This does not apply to sub-floor vents.

An external escape stair is an unenclosed escape stair , which is open to the external air and provides occupants with an escape route , which leads to a place of safety . They present additional hazards to occupants evacuating a building in the event of fire. This is because the escape stair will be exposed to the possible effects of inclement weather and occupants who are unfamiliar with the escape routes can feel less confident using an unenclosed stair high above the ground.

Therefore, an external escape stair should only serve a building where:

the top most storey height is not more than 7.5m, and

the building or part of the building is not accessible to the general public, and

in the case of a residential care building or a hospital , the stair is intended to be used by staff only.

In order to protect the occupants from fire and smoke during evacuation, the external escape stair should be protected against the outbreak of fire from within the building . Where the escape stair which has a total rise of more than 1.6m, every part of the external wall including fixed windows or glazing, self-closing fire doors (other than a door opening from the top storey) or any other opening not more than 2m from the escape stair, should have a short fire resistance duration. Fire protection below an escape stair should be extended to the lowest ground level.

An external escape stair with a total rise of not more than 1.6m from which occupants can freely disperse, is considered to be low enough above the ground to present minimal risk to occupants leaving the building and as a result, fire protection need not be provided.

Due to the likely smoke dissipation to atmosphere; service openings including ventilation ducts not more than 2m from the escape stair may be protected by heat activated sealing devices or systems.

Escape across flat roofs and access decks can be hazardous because the surface can be exposed to adverse weather conditions and in the case of flat roofs , may also have obstructions or no edge protection. Therefore, escape routes over flat roofs should only be used where the building or part of the building is inaccessible to the general public and there is more than 1 escape route from the room or storey leading to the flat roof .

In order to protect occupants from fire, a flat roof or an access deck forming part of an escape route should have medium fire resistance duration for the width of the escape route and for a further 3m on either side of the escape route . Every wall not more than 2m from either side of the escape route , should have a short fire resistance duration up to a height of at least 1.1m measured from the level of the escape route .

In addition, there should be no exhausts of any kind less than 2m from the escape route unless protected by heat activated sealing devices or systems (see clause 2.1.14). A wall or protective barrier at least 1.1m high may be necessary on each side of the escape route or along the edge of the access deck when the escape route is across a flat roof or access deck (see Section 4 Safety).

2.9.38 Final exits

The final exit to a place of safety at ground level, should present as little restriction as possible to occupants using wheelchairs or having other disabilities. Final exits should therefore be provided with:

a level platt except for any nominal slope for drainage having an area of at least 1.2m x 1.2m, and

a threshold that does not form a trip hazard and will permit unassisted egress to occupants in a wheelchair (see Section 4 Safety).

When altering existing buildings , it may not always be reasonably practicable to achieve the above recommendations.

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