Start with the building and escape strategy
Identify the existing and proposed use, storeys, escape routes and relevant fire separation. In a loft conversion, the route from the new accommodation to an exit can affect doors and spaces on lower floors. Redbridge's loft guidance highlights the need to address fire safety as part of the conversion rather than only within the new room. [3]
Do not assume that fitting an escape window or a domestic suppression system automatically makes any open-plan layout acceptable. The design needs a coordinated assessment of the building's circumstances and the applicable guidance. [2]
Fire protection is a complete detail
Where fire-resisting construction is required, the specification must address the whole assembly, its junctions and relevant penetrations. Structural members, doors, walls and service openings should not be considered independently where they form one fire-protection strategy. [2]
Show the intended construction and relevant product evidence before work is concealed. A late change to a ceiling, door set or service route should be reviewed for its effect on the agreed design. This is part of the designers' and contractors' continuing compliance responsibilities. [4]
The second-staircase change
From 30 September 2026, the published Approved Document B guidance recommends more than one common stair for blocks of flats with a storey 18 metres or more above ground level. The threshold is not simply “strictly above 18 metres”, and the published transitional arrangements need checking for qualifying earlier applications. This should not be presented as a blanket requirement to retrofit every existing block. [5] [2]
Separately, work within the higher-risk building regime requires the appropriate BSR process. Building height alone should not be used as a complete description of all the regime's scope and procedures. [6]
Inspection and handover
Agree inspection points before fire-resisting construction is covered and before service penetrations become inaccessible. For buildings where the fire-safety information handover provisions apply, supply the required information to the responsible person through the completion arrangements. [7] [8]
A final certificate does not replace the building's ongoing fire-safety management duties or turn the building control inspector into its fire-risk assessor. Keep the approved design and handover information available for those responsible for the completed building. [8] [9]
Published future changes
Further Approved Document B changes remove national BS 476 fire-resistance classifications from its guidance from 2 September 2029, subject to transition. Do not apply future provisions merely because they appear in the same consolidated PDF as today's guidance. [2]