If a fire door opens onto a stairwell is there a minimum distance that the landing should measure.

Regards

Stan

There is no minimum distance that the landing should measure it just means you will need addition smoke detectors.

Where smoke alarms are installed, no bedroom door should be further than approximately three metres from the nearest smoke alarm. This is because as the smoke percolates from a room on fire it cools and loses buoyancy and may not reach the smoke detector; also as the smoke detector operates its sounder has to penetrate into the rooms to wake the occupants.

At least one smoke detector should be located between every bedroom and every other room in the dwelling, other than a toilet, bathroom or shower room. In a single-storey dwelling protected by a single detector, the detector should be as close as possible to living accommodation. However, where such rooms are located on both sides of any bedroom, a smoke detector should be sited mid-way between the doors to these rooms.

The guidance is BS 5839-6:2013 Fire detection and fire alarm systems for buildings. Code of practice for the design, installation, commissioning and maintenance of fire detection and fire alarm systems in domestic premises, and there are more items to consider depending on the size and layout of the property. The manufacturer's instructions should detail all the necessary information that comes with the smoke detector.