Most internal doors in a typical two-storey house don’t need to be fire doors at all. But add a loft conversion, build a three-storey home, connect an integral garage or live in a flat, and the rules change. This guide explains FD30 door requirements in plain English: what the rating means, where fire doors are expected in homes, and what to check so the door actually performs.
We’ve based it on Approved Document B, Volume 1 (Dwellings), which is the official guidance for meeting the fire safety parts of the Building Regulations in England. Wales, Scotland and Northern Ireland have their own guidance, so check locally if your project is outside England, and always confirm the details with your building control body.
What does FD30 mean?
FD30 describes a fire door that holds back fire for at least 30 minutes when tested to the British standard BS 476-22. The rating refers to integrity: how long the door stops flames and hot gases getting through.
An S on the end (FD30S) means the door also restricts the passage of cold smoke, usually with smoke seals fitted around the frame.
You’ll also see European classifications, such as E 30 Sa. “E 30” is 30 minutes’ integrity tested to the European method (BS EN 1634-1), and “Sa” is the smoke control classification. Approved Document B currently accepts either route.
There’s also FD20 (E 20), a 20-minute rating that comes up a lot in houses.
Where fire doors are needed in a house
Two-storey houses
If no floor is more than 4.5m above ground level, Approved Document B doesn’t usually ask for fire doors on the stairs. Instead, habitable rooms upstairs need either an emergency escape window (or external door) or direct access to a protected stairway. In practice most two-storey homes rely on escape windows.
Three storeys or more
Once a house has a storey more than 4.5m above ground, the guidance calls for a protected stairway. That’s a stair enclosed by fire-resisting construction (minimum 30 minutes) running down to a final exit, or to two separate ground-floor exits. Doors that open onto that protected stairway in a single-family house need a minimum of FD20 (E 20).
Houses with two or more storeys above 4.5m need further measures on top of this, such as an alternative escape route from storeys above 7.5m or sprinklers. That’s a job for your designer and building control.
Loft conversions
Loft conversions are where most homeowners first meet fire doors. When a conversion creates a new storey above 4.5m, the guidance says the whole escape route needs to be addressed, and fire-resisting doors (minimum E 20) and partitions (minimum REI 30) should be provided, upgrading the existing doors where necessary. If the layout downstairs is open plan, new partitions may be needed to enclose the escape route.
There’s an alternative approach for open-plan layouts that uses sprinkler protection plus a fire-resisting partition and door to separate the ground floor from the upper floors. Again, agree this with building control before you start.
Where existing doors have historical or architectural merit, the guidance suggests investigating whether they can be kept and upgraded rather than replaced.
The door to an integral garage
The door between a house and its garage is the main place a house needs a full FD30S door. Table C1 of Approved Document B sets a minimum of E 30 Sa / FD30S here, and it should be fitted with a self-closing device.
Other fire-resisting walls
Any other door in fire-resisting construction within a house needs a minimum of FD20 (E 20).
Why FD30 doors are used where FD20 is enough
Approved Document B sets minimum standards. FD30 doors exceed the FD20 minimum, and they’re what most suppliers stock as standard, so they’re commonly fitted on protected stairways and loft conversion landings. Using a higher-rated door is fine, provided the whole doorset (frame, seals and hardware) is fitted correctly.
FD30 requirements in flats
In blocks of flats, the rules are tighter:
- Flat entrance doors that open onto a common corridor or lobby need a minimum of FD30S (E 30 Sa) and a self-closing device.
- Doors onto a protected entrance hall or landing inside a flat need a minimum of FD20 (E 20).
In England, the Fire Safety (England) Regulations 2022 add duties for the building’s responsible person. In residential buildings with two or more flats and common parts, residents must be told to keep fire doors shut, not tamper with self-closers and report faults. Where the building is above 11m, the responsible person must check communal fire doors at least every three months and use best endeavours to check flat entrance doors at least every 12 months, including that self-closers work.
Do fire doors at home need self-closers?
Approved Document B says all fire doorsets should have a self-closing device, with some exceptions. Those exceptions include fire doors within flats and dwellinghouses, cupboard doors and service duct doors normally kept locked.
So, in summary:
- Doors on a protected stairway inside your house: a self-closer isn’t required.
- The door between the house and an integral garage: self-closer required.
- A flat entrance door onto a common area: self-closer required.
Doors to and within flats and houses also don’t need “Fire door keep shut” signs.
If you do fit a closer to a concealed or flush door, our guide to concealed door closers covers the options.
What makes a fire door actually work
A fire-rated leaf on its own isn’t a fire door. Approved Document B is clear that test evidence must apply to the complete installed assembly, and that small differences in detail can significantly affect the rating. Here’s what to check:
The frame and seals
Use a frame (lining) suitable for fire doors, with intumescent seals that expand in a fire to close the gap. Our FD30 fire-rated door lining is one example. Most timber FD30 leaves are 44mm thick, compared with 35mm for a typical standard internal door, so the lining needs to suit.
The gaps
The BWF Fire Door Alliance says the gap between the leaf and frame should generally be between 2mm and 4mm along both long edges and across the top. Always check the door manufacturer’s data sheet. The bottom gap is usually around 8mm to 10mm, but it should be reduced to about 3mm where smoke control is needed, unless a smoke seal closes the gap.
Hinges and hardware
Unless they’ve been tested as part of the doorset, the essential parts of hinges on a fire door should be made from materials with a melting point of at least 800°C. Use fire-rated hinges, latches and locks, and fit intumescent protection where the manufacturer specifies it.
The label and paperwork
Certified fire doors usually carry a label or plug on the top edge with a unique number that traces back to the certificate. Keep the paperwork, as it tells you which frames, seals and hardware are compatible.
No DIY modifications
Certificates commonly forbid cutting glazing apertures or trimming the door beyond set limits on site. If you want a glazed fire door, buy one that’s factory glazed, such as those in our glazed fire doors range.
Pocket and concealed fire doors
Fire doors don’t have to be standard hinged doors. Tested FD30 pocket door systems and FD30 concealed (flush to wall) doorsets are available, but the rules are stricter because the whole system has to be tested together. See our guides to FD30 pocket doors and FD30 concealed doors for the details.
What changes in 2029
The online version of Approved Document B Volume 1 includes amendments that take effect on 2 September 2029 in England. They remove the national (BS 476) classes for fire resistance, so fire doorsets will need to be classified to the European standard (BS EN 13501-2), tested to the BS EN 1634 methods. Transitional arrangements apply to projects already submitted to building control and started in time.
For homeowners, the practical message is simple: when you buy a fire door, look for evidence of European classification (such as E 30 Sa) as well as the familiar FD30 rating, particularly for projects that will run past 2029.
Frequently asked questions
Do I need fire doors in a two-storey house?
Usually not, if no floor is more than 4.5m above ground and the upstairs habitable rooms have suitable escape windows. The door to an integral garage is the main exception, which needs FD30S with a self-closer.
Do I need FD30 doors for a loft conversion?
Approved Document B asks for a minimum of E 20 (FD20) doors on the escape route when a loft conversion creates a storey above 4.5m. Many people fit FD30 doors because they’re widely available and exceed the minimum. Building control will confirm what your project needs.
What’s the difference between FD30 and FD30S?
Both resist fire for at least 30 minutes. FD30S also restricts cold smoke, normally using smoke seals. FD30S is required for flat entrance doors and doors between a house and an integral garage.
Do fire doors inside a house need closers?
No. Approved Document B exempts fire doors within dwellinghouses and flats from the self-closer recommendation. The garage door and flat entrance doors are not exempt.
Can I cut down or glaze a fire door myself?
Only within the limits set out on the door’s certificate or data sheet. Glazing apertures normally need to be cut by the manufacturer or a licensed processor, and trimming beyond the stated limits can void the rating.
Find the right fire door for your project
Browse our FD30 fire doors, or contact our team if you need help matching a fire door, frame and hardware to your project.
