Further notes on the installation of different types of systems may be found here.

LD1 A system installed throughout the dwelling incorporating detectors in all circulation spaces that form part of the escape routes from the

dwelling and in all rooms and areas in which fire might start, other than toilets, bathrooms and shower rooms.

LD2 A system incorporating detectors in all circulation spaces that form part of the escape routes from the dwelling, and in all rooms or areas that present a high fire risk to occupants.

LD3 A system incorporating detectors in all circulation spaces that form part of the escape routes from the dwelling.

PD PD1 A system installed throughout the dwelling incorporating detectors in all areas in which fire might start other than toilets, bath and shower rooms.

PD2 A system incorporating detectors only in defined rooms or areas of the dwelling in which the risk of fire to property is judged to warrant their provision.