The creation of a Habitable room in the roof space i.e. a bedroom, study, playroom, or office, etc, that is accessed by a new fixed stair will require a Building Regulations application.
If a dormer window or an increase in volume is required for the conversion, planning permission may also be required.
Loft conversions can be expensive and it is worth considering room loss in providing the new stair to the loft and whether the net gains will be acceptable.
Loft conversions are not simply a case of providing a floor and boarding of ceiling joists several important points need to be considered.
The creation of the new room is likely to require steel members to support the new floor and strengthening to the existing rafters, decreasing apparent headroom by 300mm or more. Couple this with the requirement to insulate the space to current requirements, a further head room loss of around 100mm can be expected. Often this makes achieving the required minimum headroom to the new stair flight of 2000mm difficult.
Loft conversions no longer require an Escape Window from the loft room. If the new habitable space is above 4.5m from ground level a Protected Route must be provided from the new loft room to external air ( the outside ), or to two escape routes at the ground floor level. This route includes the existing stair enclosure which must be upgraded to provide 30 minute fire resistant construction.
Fire Resistant Construction
To achieve 30 minute fire resistant construction:
all doors to habitable rooms and the kitchen, if accessed from the Protected Route,must be replaced with FD30 fire doors and door sets. Self closers are only required to garage doors.
The loft room must have a fire door either at the top or bottom of the new stair.
The new loft floor must also be constructed to provide 30 minute fire resistance, and in some cases parts of other habitable rooms may need upgrading if they adjoin the Protected Route.
A mains operated interlinked smoke alarm is required, which should have a detector on each level of the house within the Protected Route ( including the loft room ). In some cases a heat detector in the kitchen area may also be requested.
If your house is open plan at ground floor level it will be necessary to separate off the Protected Route with a new fire resisting partition at ground floor to enable exit to external air.
Forming a loft room in a bungalow is not as onerous as you are only creating a two storey dwelling, Means of Escape windows can be fitted to the new rooms created instead of creating a protected route
If you have any concerns about developing your property please feel free to contact the Building Control department for advice on construction methods and regulatory compliance.