Domestic smoke detectors come in two basic types -

The Ionisation smoke detector

These work by measuring the reduction of an electric current when smoke particles enter a special chamber. False alarms can be caused by burning toast etc, so if the detector is in a hallway near a kitchen, an optical detector may be a better choice.

Optical smoke detector 

These contain a small photoelectric cell which triggers the alarm when the beam is disturbed by smoke. False alarms may be caused by steam, so if the detector is sited near a bathroom an ionisation type may be a better choice.

When purchacing a smoke detector, ensure it complies with a British Standard (BSI Kitemarked) or an international Standards Organisation (ISO) standard. A self contained smoke detector must comply with British Standard 5446 part1 1990 for automatic fire detection and to British Standard 5839 part 1 1998 for alarm systems.

Prior to the 2006 changes to the Building Regulations, an escape window was generally required in loft conversions where the conversion created a third storey. Loft conversions carried out under the 2006 guidance however generally no longer need escape windows.

All doors opening onto the stairwell need to be FD20 fire doors - but as these are not readily available we reccommend that you use FD30 fire doors and the corresponding door frames fitted with intumescent strips. Self closers are not required unless the door opens into a garage.

The door into a garage should be a FD30 fire door and is the only one in a dwelling that needs to have an intumescent smoke seal and be fitted with a self closing device. Do not forget that the door must be fitted with 3 steel hinges. The 100mm step down into the garage can be omitted if the garage floor slopes away from the fire door and towards the front garage door.