Fire Safety Implications of Home Improvements: Altering the Internal Layout of Residential Buildings by Adding or Removing Internal Walls

Building a new wall to subdivide a room or create a new room can affect the means of escape from fire. If in doing so a situation is created whereby the route for leaving an existing or new room is only possible through another room then an egress (escape) window from the existing or new room (inner room) will be needed as well as, possibly, one or more smoke alarms.

If the floor level of the inner room is greater than 4.5m above ground level (as with the top floor of a typical three storey house for example) the use of an egress window may not be safe and therefore an alternative solution will need to be sought. This may well be one that does not create an inner room situation in the first place.

Some walls around stairways (typically in houses 3 storeys or more in height) need to have fire resistance to ensure a fire in one of the rooms off of the stairway doesn’t unduly affect the means of escape from other rooms in the house. In other houses (such as in two storey houses) the walls may not need to have any particular fire resistance, but would still afford some protection to the stairway by containing the fire and smoke for a period of time.

The impact of the removal of an internal wall on fire safety should be carefully considered. In two storey houses, the removal of such a wall could normally be compensated by the provision of mains powered interlinked smoke alarms and egress windows from the other rooms off the stair. However, in houses of three storeys and greater this compensation may not be sufficient. The exact features needed will vary on a case by case basis.

A new wall (including any door leading through it), which separates a room from the stairway may need to have adequate fire resistance (typically in three storey houses) and, in the case of a door, be self closing.

The Advantages of Using Fire Curtains to Comply With Approved Document B (fire safety), Part B (2006 Ed., amended 2007)

This document sets out defining principles for building control and design in the UK. Volume 2 Part B specifically looks at fire safety in buildings other than dwellinghouses. The five key aspects the document identifies are shown below. In particular points B1 and B5 reference the requirement to provide protected means of escape, and to slow the passage of fire through a building to both protect the occupants and aid the fire service. BLE smoke and fire curtains are perfectly designed to help achieve these goals whilst having the advantage of remaining hidden and out of the way during times of normal building use. Our curtains boast significant aesthetic, weight and cost advantages over bulky fire shutters and expensive glass screens to achieve the best possible finish without compromising on fire safety.

Part B. Fire safety

The Regulations consider five aspects of fire safety in the construction of buildings:

B1 Means of escape
1. That sufficient provisions are made in design of the building so that in the event of fire the occupants can escape to a place of safety by their own efforts. This includes incorporating a suitable fire alarm system to give early warning of fire to the occupants and users of a building.

B2 Internal fire spread (linings)
2. That the internal linings of a building do not support a rapid spread of fire

B3 Internal fire spread (structure)
3. That the structure of the building should not collapse prematurely and should slow the spread of fire through the building and in unseen cavities and voids by providing fire resisting walls and partitions where necessary;

B4 External fire spread
4. That the spread of fire between buildings be discouraged by spacing them apart sufficiently and controlling the number and size of openings on boundaries;

B5 Access and facilities for the fire service
5. That the building (and the site layout & access roads) are designed in such a way as to aid the fire brigade fight fire and effect rescue of persons caught in a fire.

Fire Compartmentation Laws for Buildings in London

The London Building Acts (Amendment) Act, 1939 Part III, Section 20 requires that large buildings are sub-divided into fire-containing zones to both protect occupants and property and slow the progress of fire throughout the building. BLE smoke and fire curtains are ideally suited to achieve such protection whilst facilitating the incorporation of open doorways and spectacular open atria that would otherwise have to be closed off using walls and fire doors.

Section 20 applies where:

• a building is to be erected with a storey or part of a storey at a greater height than (i) 30 metres; or (ii) 25 metres if the area of the building exceeds 930 square metres
• a building of the warehouse class, or a building or part of a building used for the purposes of trade or manufacture, exceeds 7,100 cubic metres in extent unless it is divided by division walls in such manner that no division of the building is of a cubical extent exceeding 7,100 cubic metres.