BCG003 Planning Considerations

Stairways

1. To ensure that the stairway will normally remain available as a route of escape in the event of a fire, the existing stair at ground and first floor level must be enclosed in fire resisting construction (e.g. 12.5mm plasterboard on timber studs at 400centres (min 100mm thick overall) or blockwork).

The route must lead to an external door at the foot of the stairs or a choice must be available to pass through one of two separate rooms to an external door. This is required so that if a fire occurred in one of the rooms, escape would always be possible through the other.

Fire Doors

2. All existing doors to habitable rooms on the escape route need not be replaced with fire doors, but all new doors must be fire doors. However by installing Nationwide Fire Sprinklers you may be able to have a dispensation from the building control officer to allow doors that match other existing doors instead of fire doors.

Glazing

3. Any glazing in partitions between a habitable room and the escape route must also be fire resisting but again you may be able to achieve a dispensation from the building control officer by using Nationwide Fire Sprinklers.

Fire Separation Gaps

4. The basic requirement for fire separation, is to surround the new rooms in such a way that if a fire did occur below, the occupants would be protected from its effects for 30 minutes.

This can be achieved by using Nationwide fire sprinklers and the new stair can continue up in the existing stair enclosure Alternatively it can be enclosed in a fire protecting structure from first floor level upwards (in which case the fire door will normally open off the first floor landing).

Fire Resistance

5. The floor to the new rooms must have a 30-minute fire resistance over any part of the escape route directly below or above. This is often the case when, for example, the floor of the new room extends over a landing in the stairway enclosure below.

Where the floor is only over other rooms a 'modified' 30 minute standard of fire resistance is required which is much easier to achieve. by using Nationwide fire sprinklers throughout the dwelling you should be able to achieve a dispensation on this point from the building control officer.

Escape Windows

6. Escape windows must normally be provided in each of the new habitable rooms. The only exception to this occurs in a two-room loft conversion, where a window in only one of the two rooms is acceptable provided each has a separate doorway onto the stairway enclosure, and there is a separate communicating door between the two rooms.

It is important that there is access and space available at ground level to allow the escape windows to be reached by a ladder; extensions or conservatories can often make this difficult.

Trusses Loft Spaces

7. Modern houses with trussed rafter roofs are usually unsuitable for loft conversions, as the inner members of the truss cannot normally be removed. While a structural engineer may be able to design a scheme to make this possible it is likely to be prohibitively expensive.

Ceiling Joists

8. The existing ceiling joists in the roof will almost certainly be inadequate for use as floor joists. In most cases it is possible to install new floor joists between the existing ceiling joists to maximise the headroom available.

Insulation

9. The new rooms will need to be surrounded by insulation to prevent excessive heat loss. While there are many ways of achieving this, there are some traps for the unwary here and we would recommend that you check your chosen method with your Building Control Officer before any insulation is installed.

Sprinkler Systems

10. New sprinkler systems designed for use in dwellings are now becoming increasingly common, and where a whole house system is fitted as part of a loft conversion scheme it may be possible to accept situations which do not fully meet the fire protection or escape requirements outlined above.

For example, new doors DO NOT require to be fire doors, any doors to be fitted with self closing devices or the upgrading of the fire resistance of walls or floors, providing the whole building is protected by a properly designed and installed sprinkler system. An escape window in the new room(s) and smoke alarms would still be required.

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There are many other areas where the Building Regulations impose requirements relating to loft conversions, but if you can deal with the points raised in this document, you will be well on your way to getting approval. If you now wish to proceed you should make either a full plans or building notice application

This guidance note deals with the points, which most often cause difficulties for applicants. If you cannot find ways of dealing with them, it may not be possible to convert your loft at all.