January 2001

Means of Escape in Case of Fire?

Part B1, Means of Escape for Buildings (other than Houses or flats),
Part B4, External Fire Spread; (See also Internal Fire Spread - Part B2, Linings, and Part B3, Structure),
Part B5, Fire Brigade Access,
Building Regulations).

Approved Documents

    Part B1, Means of Escape

  1. Are there any requirements to ensure wheelchair users are able to escape in the event of fire?
    A new 3 storey office building has a basement storey. There is to be lift access and a stair to the basement which has training facilities and a canteen. What requirements need to be provided to ensure that, in addition to management facilities, wheelchair users are able to safely escape from fire?
  2. A hospital is being refurbished. The Hospital Management ask, can a rear final fire exit door be provided with a lock, to prevent unauthorised exit by thieves? Is this acceptable? How could the conflicting requirements of security and fire safety be met?
  3. A new office has a single stair access, but no lift, to the top floor. There are to be 6 people working on this floor. It is proposed to have a handrail on both sides of the stair. The handrail is to project 100mm inwards from the wall on one side and the balustrade on the other side. What distance is required between the handrails for:-
    1. adequate means of escape in case of fire, and
    2. access for ambulant disabled persons?
  4. A tall office building is to use phased evacuation as a means of reducing the neccesary width of stair for a full evacuation. What precautions are necessary to ensure adequate means of escape?
  5. An Architect is drawing up plans for a large open-plan type of offices. The area of the offices is such that at least two and possibly three stair cores are going to be needed. What is the maximum distance possible between stair cores?
  6. A 2 storey office block is to have a boiler room on the top floor. The stairs leading to the top floor has a door separating it from a corridor. The corridor leads to both offices and the boiler room. What precautions are necessary, to ensure a fire in the boiler room would not prevent adequate means of escape from the top floor offices?
  7. An existing single stair office block has a large entrance hall. The designer asks you if it is OK to have a reception desk in this entrance hall?
    If there were two stairs would your answer be different?
  8. You visit an office undergoing rehurbishment and you notice a copper pipe has been installed in a stairwell. Upon enquirey you are informed that this is a new gas pipe to allow a gas cooker to be fitted in the top floor staff kitchen. Is this OK?
  9. A warehouse is to have a new internal office installed. There are no external windows to this office. The designer asks is it necesary to install an emergency lighting unit to the room? The travel distance is such that a new exit door to the outside is to be installed in the warehouse. The designer asks what size should the Exit sign be over the door?
  10. It is proposed to create an internal office room off an open plan office area. The Approved Document gives 3 ways to ensure that occupants of the inner room are given adequate warning of a fire in the access room. What are they?
    If the outer room was to be sub-let to a tenant, would that make any difference?
  11. A new office block is to have two stairs and contain 60 people on the upper floors. Occupants on the ground floor have exit doors independant of the stairs. What is the minimum width of each final exit door from the stairs?
  12. You are examining plans of a new office building. The plans show a plant room in the basement off a corridor leading to an external door to a lightwell with externasl stairs. The drawing does not show the arrangement of the plant. What is the maximum direct travel distance from any part of the room to the only door from the plant room?
    Would your answer be different if the drawing did show the arrangement of the plant?
  13. A new cinema is to have a single aisle down the centre of the seating area. What is the maximum number of seats in each "one-way-out" row?
    If the Architect propsed increasing the width of the walkways, could the number of seats in each row be increased?
  14. A new golf clubhouse extension is to be built. The bar standing area is to be 10m by 3m.
    1. What is the maximum number of people that could be accomodated in this space?
    2. Why is it NOT acceptable for this number of people to have only one way out?
    3. If there are two ways out from the bar at each end of the room, what is the minimum width of each door?
    4. Do the exit doors have to open outwards from the room or can they open inwards?
    5. If one of the doors goes to the outside, can a lock be provided on the door with a "turnbuckle" handle on the inside to over-ride the lock?
  15. An existing 2 storey office building has a single stair in the centre of the building. At the top of the stair is a door to a fire resisting lobby. The lobby has 2 doors, each leading to an office. The occupier of the building wishes to remove the fire-resisting lobby so that people can go directly from the stair into either office. What is the reason for the fire-resisting lobby?
    Assuming that the stair leads down to a final exit on the ground floor without passing through any accomodation, what could be accepted as a reasonable "Trade off" to the recommendations of the Approved Document?
    Before agreeing to any "Trade-off" should the "Fire Authority" be Consulted?
    If the owner proposed removing a down stairs corridor, so that after descending the stairs it was necessary to enter a door into existing accomodation, where does the Approved Document advise against this?
  16. A new school is to be built. The Archtect asks does Emergency Lighting have to be provided and if so where should the lighting units be located? Would your answer be different if the building was a residential home for old people?
  17. Part B4, External Fire Spread

    Fire Brigade Pump
  18. A 5 storey block of flats is to have its walls over-clad with polystyrene and finished with a thin non-combustible rain proof resin. The Fire Authority have had their attention drawn to this proposed upgrading by tenants of the building. The Fire Authority are concerned that a fire in one flat could quickly spread up the face of the building to the roof. With the roof on fire it might not be possible to save the building and there could also be danger to life safety. Assuming that the building is more than 1.0m away from its site boundaries, is there any control on the external surfaces of the walls?
    If the building had been a school, would your answer to the fire brigade have been different?
  19. An owner of a semi-detached house wants to have a window installed to the side of the house. The boundary with the neighbour is 800mm away from the window. What is the maximum size of window that could be installed without any fire spread issues?
    If the owner wanted a window larger than this limit, how might this be accomodated?
  20. An owner of a 5.0m wide terraced house wishes to build a single storey rear extension 4.0m wide and 4.0m deep into the rear garden. There is to be a fully glazed door on the side wall of the extension which will be 1.0m from the boundary. A neighbour telephones to ask if there is a possible problem with fire spreading accross to their property in the event of a fire?
  21. A loft conversion is being done to a 2 storey terrace house. An escape roof window is to be installed in the line of the roof 0.6m away from one party wall. Which of the following materials can be used in the roof window:-
    1. 4mm thick unwired glass
    2. Polycarbonate plastic tested to achieve BS 476 Part 7 Class 1 standard
    3. Plastic roof light tested to achieve BS 476 Part 7 Class 3 standard

    If the roof light had been over a protected stairway, would your answer have been different?
    If the roof light was in a roof slope facing another roof slope accross a boundary would you answer have been different?
  22. A new 10m high industrial storage building is to be erected beside a road. The distance to the centre of the road is 5.0m. It is proposed to have a brick wall on the lower part and metal sheeting to the upper part. If the height of the side of the building is 9.0m, how high should be the brick wall?
    If it was proposed to install an automatic sprinkler system would that change your answer?
  23. The chairman of a carnival club is looking to build a large garage unit for the purpose of housing their carnival float, and thus assisting the charitably causes that they raise money for each year. They hope to build a steel-framed building, measuring approximately 30M long x 12M wide x 7M high, with coated steel cladding. As their site is on a boundary,they are considering how far to move the building away from the boundary before the fire resistance is no longer a requirement.

    Part B5, Fire Brigade Access

    Fire Brigade Access
  25. A 4 storey new office block is to be 60m by 10m in plan area with a stair and lift core at each end. How many fire fighting shafts are needed?
    If the office building had only been 59m long would a fire fighting shaft have been needed?
    The Fire Authority suggest that they would like to see the outlet from the fire main in the fire-fighting stair. Is this acceptable?
    If the fire-fighting lobby is to be vented by a shaft with air inlet grills at ground level and automatic opening vents at roof level, how large should be the ventilation shaft?
    If the required ventilation to the fire-fighting stairs is to be provided by electrically operated windows, where should the firemans switch be located?
  26. A new office block is to have a basement storey. As the site is a congested inner-city one it is proposed to provide a mechanical smoke extract system instead of a natural smoke outlet ventilation. What precautions are necesary to ensure this works satisfactorilly.
  27. A sprinkler system is to be installed in a basement storey of an existing shopping centre. The Architect asks does the sprinkler system have to be a life safety system or would the normal one be acceptable?
    What are the key differences between a life safety sprinkler system and a normal sprinkler system.
  28. What is the furthest distance a fire pump should have to travel into a site before it is necessary to provide a turning circle or "hammer-head" turning facility?
  29. Building Regulations

  30. Does the Fire Brigade have to be consulted, and "Full Plans" deposited, when building work involving fire safety is proposed to ANY workplace, other than houses and Flats?
  31. You receive a complaint that a builder has installed a new sink in an office which has stopped working. Thinking this might be building work done without giving the required notification to the Local Authority, you visit the flat. You find that the sink has been plumbed into a "dry riser". The owner decides not to have a new sink after all. Under what Regulation do you ensure that the damaged dry riser is replaced with one able to take the pressure of a fire pump?

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Updated on 3rd March 2001 by Robert Hunter-Jones MSc CEng MICE MIStructE FRICS

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