Fire door checker
Three questions about where the door is going, and a plain-English answer on what is typically specified there — plus, where the honest answer is that a website cannot tell you, we say so.
Every scenario this tool covers
Between an integral or attached garage and the house
A fire door is normally specified here — commonly FD30 (30 minutes), usually with a self-closing device.
[VERIFY: Approved Document B Vol 1 — garage / dwelling separation clause]
A garage holds a car, fuel, and usually paint, solvents and garden chemicals. The door into the house is the only thing between all of that and your stairs.
- The threshold detail is commonly specified alongside the door — typically a step up into the house, so that spilled fuel cannot run underneath it. [VERIFY: Approved Document B Vol 1 — threshold detail]
- In an otherwise ordinary two-storey house, this is usually the only fire door in the building.
Before you order: confirm this with your local authority building control or an approved inspector. They decide, not us.
A loft conversion — the new stair, or the rooms opening onto it
Converting a loft normally makes the house three storeys, which usually brings a requirement for a protected stairway running all the way to a final exit. Habitable rooms opening onto that stair are commonly specified as FD30 with self-closing devices — on the floors below as well as the new one.
[VERIFY: Approved Document B Vol 1 — loft conversion and protected stairway clauses]
From a converted loft there is usually only one way out, and it runs past every other room in the house. The doors are what keep that route usable long enough to use it.
- A loft conversion is notifiable building work, so a building control body is already involved. The fire door specification will be in your approval — ask for it before you order, not after the doors arrive.
- People are often surprised that the existing doors downstairs are in scope too. Budget for the whole set, not just the new floor.
Before you order: confirm this with your local authority building control or an approved inspector. They decide, not us.
A habitable room opening onto the stairway — three or more storeys
FD30 doors with self-closing devices are commonly specified on habitable rooms opening onto the protected stairway of a house of three or more storeys.
[VERIFY: Approved Document B Vol 1 — dwellings of three or more storeys]
You cannot reasonably expect anyone to escape from a second floor through a window, so in a taller house the stair itself has to be protected and has to stay usable while people come down it.
- Count a converted loft as a storey. It is the most common reason an ordinary house becomes a three-storey one.
Before you order: confirm this with your local authority building control or an approved inspector. They decide, not us.
A habitable room opening onto the stairway — two-storey house
Ordinary internal doors are normally acceptable here. Two-storey houses usually rely on escape windows from the first floor rather than a fully protected stair, so fire doors are not generally specified on room doors.
[VERIFY: Approved Document B Vol 1 — two-storey dwellings]
The escape strategy for a standard two-storey house does not usually depend on the room doors holding a fire back, so specifying fire doors throughout is not normally required.
- The door to an integral garage is the usual exception, whatever the number of storeys.
- If the house has been altered — a room in the roof, an open-plan ground floor, or a stair that opens directly into a living room — the standard answer often stops applying. Those are exactly the cases to put to building control rather than to a website.
Before you order: confirm this with your local authority building control or an approved inspector. They decide, not us.
Between two rooms, away from the stairs
Normally an ordinary internal door. A door that is not on an escape route is not usually where fire resistance is specified.
[VERIFY: Approved Document B Vol 1 — dwellings]
Fire doors in homes protect the route out. A door between two rooms that both open onto that route is not doing that job.
- A door into an integral garage, a plant room, or a room in the roof is a different question even if it looks like an ordinary internal door.
Before you order: confirm this with your local authority building control or an approved inspector. They decide, not us.
An understairs cupboard inside the stairway enclosure
Where a cupboard sits inside a protected stairway, the enclosure — including its door — is normally required to be fire-resisting.
[VERIFY: Approved Document B Vol 1 — protected stairway enclosure]
The understairs cupboard is where the consumer unit, the meter and the household clutter live, and it sits inside the one route everybody in the house has to use.
- This applies to the cupboard door specifically. It is easy to miss when the rest of the hall is being reworked.
Before you order: confirm this with your local authority building control or an approved inspector. They decide, not us.
A flat or maisonette in a block
This tool cannot answer for your building — and you should not buy a door until somebody who can has answered.
[VERIFY: the fire strategy and the regulations applying to your building]
Flat entrance doors and doors onto communal escape routes are governed by the building's own fire strategy and by duties placed on the building's responsible person. The right door is the one that building's strategy specifies, which is not something a website can work out from three questions. Changing one without approval can also breach your lease and compromise the escape route for everybody else in the block.
- Speak to your freeholder or managing agent, and to your local authority building control, before ordering anything.
- This applies to the flat entrance door in particular, which is part of the communal escape route even though it is your front door.
Before you order: confirm this with your local authority building control or an approved inspector. They decide, not us.
An HMO, a rented property with shared areas, or a commercial building
This tool cannot answer for your building. The specification comes from the building's fire risk assessment.
[VERIFY: the building's fire risk assessment and the regulations applying to it]
These buildings carry duties on a named responsible person, and a fire risk assessment that sets out what each door has to do. Buying to a guess exposes you, and anybody living or working there.
- Get the door specification from the fire risk assessment, or from a competent fire safety professional, and confirm it with building control.
Before you order: confirm this with your local authority building control or an approved inspector. They decide, not us.
Three things that apply either way
What the ratings mean
FD30 and FD60 are the fire resistance periods the notation describes — thirty and sixty minutes. You will also see them written with an S, as FD30S; in trade usage the S denotes smoke control, meaning cold smoke seals in addition to the intumescent seal. [VERIFY: source for the S designation]
The rating belongs to the assembly
A fire rating is a property of the complete doorset — leaf, frame, intumescent strips, smoke seals, hinges, latch, any closer, any glazing, and the gaps it is hung with. A certified leaf hung in the wrong frame, or on the wrong hinges, is not a rated doorset. Keep the certification paperwork; building control will ask.
Which rules apply where
In England the statutory guidance for Part B of the Building Regulations 2010 is Approved Document B (Fire safety), Volume 1: Dwellings, with Volume 2 covering buildings other than dwellings. Wales, Scotland and Northern Ireland each run their own systems. [VERIFY: exact document titles for Wales, Scotland and NI]
Common questions
Does this tool tell me whether I legally need a fire door?
No. It tells you what is typically specified in a situation like yours, so you know what to ask and roughly what to budget. The decision belongs to your local authority building control or an approved inspector. In England the relevant statutory guidance is Approved Document B (Fire safety), Volume 1: Dwellings; Wales, Scotland and Northern Ireland run their own systems. Confirm before you order, because a fire door and an ordinary door look similar and cost differently.
What is the difference between FD30 and FD60?
The number is the fire resistance period the notation describes: FD30 is thirty minutes, FD60 is sixty. You will also see the ratings written with an S, as FD30S, which in trade usage denotes smoke control — cold smoke seals in addition to the intumescent seal. Which of them applies to a particular door is a question for building control, not one this tool can settle.
Can I fit a fire door leaf into my existing frame?
A fire rating is a property of the complete doorset — leaf, frame, intumescent strips, smoke seals, hinges, latch, any closer, any glazing, and the gaps it is hung with. A certified leaf hung in an unsuitable frame or on the wrong hinges is not a rated doorset. Keep the certification paperwork, because building control will ask for it.