Fire safety for London offices

Both, and the split is the thing that catches people out. In a multi-let building the landlord or managing agent is normally the responsible person for the common parts, the stairs, the main alarm panel and the building’s escape routes. You are the responsible person for the area you occupy, which means your fire risk assessment, your staff training, your extinguishers and your own arrangements for getting people out. Article 22 of the Fire Safety Order goes further and requires responsible persons sharing a building to co-operate, co-ordinate and tell each other about risks. In practice that means asking for the building’s assessment and evacuation strategy in writing, and making sure yours does not contradict it.

The fire risk assessment decides, and the vocabulary matters because two of the categories are routinely misread. L4 covers the escape routes only. L3 adds the rooms that open onto those escape routes, which is what most offices end up with, because a fire starting in a room next to the corridor is the one that traps people. L2 is L3 plus specific high-risk areas named in the assessment, such as a server room or a plant room, rather than a coverage level between L1 and L3. Full coverage of every room is L1 and is rarely justified in an office with no sleeping risk.

Almost never the fix people reach for, which is disabling the zone. An optical smoke detector reads toast and steam as smoke because in optical terms they are very similar. The correct answer is detector selection: a heat detector or a multi-sensor in that specific position, sited away from the toaster and the kettle, sometimes with a short verification delay on the panel. That keeps the coverage the assessment asked for and stops the false alarms. A zone left isolated after an evening call-out is the failure we find most often, and it is the one that shows up on the panel log.

Not necessarily. Taller buildings often use phased evacuation, where the floor of origin and the floor above leave first and the rest follow in sequence, so the stairs do not have to carry the whole building at the same moment. That strategy relies on the compartmentation actually holding, on the alarm being able to sound different messages on different floors, and usually on a voice alarm system rather than sounders. It is a decision that belongs to the building’s fire strategy and the assessment, not to a tenant, and it is one of the things to ask the landlord for in writing.

Two fire alarm service visits under BS 5839-1, with a certificate each time, plus the weekly test you carry out yourself and record. Emergency lighting needs a monthly function test and an annual full-duration test under BS 5266-1, and since the 2025 edition also a photometric verification at least every five years, which is a measured check that light levels still match the design. Extinguishers need a monthly visual check by you and an annual basic service. The fire risk assessment itself has to be reviewed whenever anything material changes and kept under regular review regardless.