Loft Conversion Fire Doors: The Escape Route, Done to Approved Document B

Converting a loft usually creates a new storey, and where that new storey is more than 4.5m above ground level, Building Regulations Approved Document B requires the full escape route from it to be addressed — fire-resisting doors, minimum E 20, and fire-resisting partitions, minimum REI 30, along the route, including upgrading existing doors where necessary. It is the height of the new storey above ground, not simply the fact that a loft has been converted, that triggers this requirement.

Not automatically — it depends on the height of the new storey above ground level and the existing escape route from the property. We confirm during the assessment visit whether your specific conversion falls within the Approved Document B threshold, and which doors along the route are affected, rather than assuming every loft conversion needs the same scope.

Where the escape route needs addressing, it is not limited to the door at the top of the new stair — existing doors lower down the escape route, for example onto the stair enclosure on the floor below, can also need upgrading to the required standard. We assess the whole route from the new storey to a final exit, not just the loft landing door, before confirming the scope.

Where the new storey is more than 4.5m above ground level, escape-route doors need to be fire resisting to a minimum of E 20, and partitions along the route to a minimum of REI 30. Escape-route doors also need to be self-closing and readily openable without undue delay to escaping occupants. We confirm the exact rating for each door on your specific route before quoting.

Our general fire doors page covers fire door installation detail for any situation — stair enclosures, loft conversions, or a general security and insurance upgrade. This page is the loft-conversion-specific deep dive: why a loft conversion in particular triggers the requirement, which doors on the route are typically affected, and how we coordinate fire door fitting with the rest of the loft conversion carpentry. The installation detail itself — intumescent and smoke seals, self-closing devices, compatible ironmongery — is the same specification covered in full on the general fire doors page.

No, and we would be cautious of anyone implying personal fire-door-installer certification exists as standard. The FD30/FD60 rating is tested and certified at the point of manufacture for the doorset as a whole — leaf, frame, seals and specified ironmongery together. Our role is installing that certified doorset to the manufacturer's fitting instructions, not certifying it ourselves. If your project specifically requires a third-party accredited installation scheme, we will tell you so.

Usually towards the end of the carpentry programme, once the stair opening is framed, the floor is strengthened and the stair itself is in, but we confirm the exact timing at the assessment visit — door openings and linings sometimes need to be allowed for earlier if the existing frames need replacing.

We can supply the doorset, sourced already manufactured and tested to the rating your loft conversion requires, or install a doorset you have already sourced — provided it is manufactured to the appropriate standard and suitable for the opening.