Homes & Let Houses · England
An integral or attached garage may contain vehicles, fuels, equipment and stored items, which is why its separation from the rest of the house matters. The door between the garage and the house is part of the separation between the two. This guide explains the official guidance for England, how it differs for existing homes, what to check and when repair or replacement fits. It is general information, not a building control decision.
Approved Document B Volume 1 (paragraphs 5.6 and 5.7, Diagram 5.1) describes the wall and any floor between a dwellinghouse and an attached or integral garage as fire-resisting construction. It shows the door between them as a fire door fitted with a self-closing device, and describes either a door opening raised above the garage floor or a garage floor that falls away from the door to the outside so that spilled fuel flows away from the house.
The document sets out its own scope, figures and exceptions. Read the relevant paragraphs and diagram rather than relying on a summary, including this one.
New work
Approved Document B is guidance on meeting the Building Regulations for building work. Where a garage conversion, extension or new build is under way, the designer and building control body will confirm what the door must achieve.
Existing
The guidance does not mean every existing garage door must be replaced immediately. The building's history, approved plans, completion records, the door's condition and a competent assessment decide what is appropriate.
Records
Building control completion certificates, plans, the original specification and any door label or documentation help establish what was intended and fitted.
These are observations to record and share, not a formal inspection. Photographs help whoever assesses the door.
Closing
Closers are sometimes removed for convenience. The door then relies on someone shutting it.
Latching
Worn hinges, a misaligned keep or an incorrectly adjusted closer stop the latch engaging.
Damage
Garage-side faces and edges take impact damage that can open gaps or split the leaf.
Alterations
Cut-outs and added fittings may put a door's evidence or performance in doubt and should be checked against its supported details.
Repair may be possible where the existing door is a fire door in sound condition and the fault is in an adjustable or replaceable component, such as a closer, hinge, latch or seal, using the doorset's supported method and compatible components.
Replacement with a suitable fire doorset may be the sounder outcome where the existing door is not a fire door, has been significantly altered or damaged, or its construction cannot be established for what is required. A missing label alone does not decide it. Our repair or replacement guide covers the wider decision.
Trimming a leaf to clear a new floor, drilling for a lock, fitting a flap or swapping hinges and closers for non-matching parts may change gaps, weaken the leaf or introduce components outside the doorset's tested or specified details. That may undermine both its performance and the evidence for it. Ask before changing anything.
GOV.UK: Fire safety: Approved Document B (publication page) — accessed 9 October 2026.
Approved Document B Volume 1: Dwellings (current online PDF) — paragraphs 5.6–5.7 and Diagram 5.1, accessed 9 October 2026. Applies in England.
Related guides and services.
Send photographs of both faces, the edges, any label and the closer, plus any building control or survey notes. We will assess the door for repair or replacement works and provide a written quotation. We do not make building control decisions or carry out formal inspections.