What does Accountable person mean?

An accountable person is the person or organisation that owns or has a legal obligation to repair the common parts of a higher-risk building in England, under the Building Safety Act 2022. Where there is more than one, the principal accountable person takes lead responsibility, including registering the building with the Building Safety Regulator. Accountable persons must assess and manage building safety risks, including fire door condition.

FD20 is a fire door rating meaning the door achieved at least 20 minutes' integrity when tested to BS 476-22. It appears in building regulations guidance mainly for some doors within dwellings, such as doors onto a protected stair in a house or a protected hallway in a flat. In practice FD30 doors are far more widely supplied, so many specifiers fit FD30 even where FD20 is the stated minimum.

What does Leaf-to-frame gap mean?

The leaf-to-frame gap is the clearance between the edges of a door leaf and its frame along the hinge side, lock side and head. On a fire door it is typically a few millimetres and must fall within the range set by the door's test evidence. Gaps that are too wide or uneven can let smoke and flames through before the intumescent seal activates.

Fire Door Glossary | 60 Terms Explained

A B C D E F G H I L O P R S T V

Accountable person: An accountable person is the person or organisation that owns or has a legal obligation to repair the common parts of a higher-risk building in England, under the Building Safety Act 2022. Where there is more than one, the principal accountable person takes lead responsibility, including registering the building with the Building Safety Regulator. Accountable persons must assess and manage building safety risks, including fire door condition.
Approved Document B: Approved Document B is the statutory guidance on fire safety supporting the Building Regulations, published in two volumes covering dwellings and other buildings. England and Wales each have their own version. It sets out where fire doors are needed and their ratings, using both national FD ratings and European classifications. In England, national BS 476 classifications are due to be withdrawn from it in favour of EN 13501, not before 2029.
Backcheck: Backcheck is a hydraulic resistance built into many door closers that slows the leaf during the last part of its opening swing. It cushions the door if it is flung open or caught by the wind, reducing damage to the leaf, hinges, walls and ironmongery. Backcheck is usually adjustable and is common on heavily used doors in schools, hospitals and student accommodation.
BS 476-22: BS 476-22 is the British Standard fire resistance test method for non-loadbearing elements, including doors. FD ratings such as FD30 and FD60 come from testing to it, measuring how long a door maintains integrity. Approved Document B still accepts these national classifications alongside European ones, although in England they are due to be withdrawn in favour of EN 13501, not before 2029.
BS 8214: BS 8214 is the British Standard code of practice for fire-resisting and smoke control doors, covering specification, installation and maintenance. The current edition, BS 8214:2026, was published on 20 March 2026, replacing BS 8214:2016. It widened the scope to steel, metal, aluminium and composite doors and strengthened guidance on sealing the gap between the door frame and the surrounding structure.
BS EN 13501-2: BS EN 13501-2 is the European classification standard that turns fire resistance and smoke control test results into ratings. For doors it uses E for integrity, I for insulation and S for smoke control, so a door might be classified E30 Sa or EI60. UK guidance is moving towards these classifications, with national BS 476 ratings due to be withdrawn from the English Approved Document B, not before 2029.
BS EN 1634-1: BS EN 1634-1 is the European fire resistance test standard for doors, shutters and openable windows. A door is tested in a furnace and monitored for integrity and, where needed, insulation. The results are classified under BS EN 13501-2, giving ratings such as E30 or EI60. It is gradually replacing BS 476-22 as the main test route for fire doors in the UK.
Building Safety Regulator: The Building Safety Regulator is the body set up under the Building Safety Act 2022 to oversee the safety and standards of buildings in England. It is the building control authority for higher-risk buildings, so work on those buildings, including some fire door replacement programmes, may need its approval. It also oversees how accountable persons manage safety risks in occupied higher-risk buildings.
Certification label: A certification label is the mark applied to a certified fire door so its scheme, manufacturer and rating can be traced. Some schemes use a tamper-evident label on the top edge of the leaf; others use a plug, often colour-coded, set into the hinge edge. A missing or painted-over label does not mean a door is unsafe, but it makes its performance much harder to prove.
Communal fire door: A communal fire door is a fire door within the common parts of a building, such as a stair door, lobby door, cross-corridor door or door to a bin store, plant room or meter cupboard. These doors protect the shared escape routes and are usually the responsibility of the freeholder, landlord or managing agent rather than individual occupiers.
Compartmentation: Compartmentation is the division of a building into separate fire-resisting compartments using walls, floors, fire doors and fire stopping, so a fire is contained where it starts for long enough for people to escape and firefighters to act. Every gap, service penetration and door in a compartment line has to perform at least as well as the construction around it.
Concealed closer: A concealed closer is a door closing device hidden within the leaf and frame so it is not visible when the door is shut. Types include closers mortised into the head of the leaf and frame, and jamb-mounted chain spring units. Concealed closers suit homes and hotels where appearance matters, but must be covered by the door's test evidence and strong enough to close and latch the door.
Door coordinator: A door coordinator, also called a selector, is a device fitted at the head of a pair of doors with rebated meeting edges. It holds the active leaf back until the inactive leaf has closed, so the pair shuts in the correct order and the meeting edges seal properly. Without one, the leaves can close out of sequence and leave a gap.
Door frame and lining: A door frame is the fixed surround secured to the wall opening that the leaf hangs in, also called a lining when formed from thinner boards with an applied stop. For a fire door, the frame's material, section size and fixings must match the door's test evidence. Architraves cover the joint between frame and wall, but the gap behind them still needs proper fire stopping.
Door leaf: The door leaf is the moving, hinged part of a door assembly, the panel that opens and closes within the frame. A fire door leaf has a tested core, lippings and facings, and its performance depends on being hung in a suitable frame with compatible hardware and seals. Fitting a fire-rated leaf into an unsuitable or damaged frame can undermine its rated performance.
Door viewer: A door viewer, also called a spyhole, is a small lens fitted through a door leaf so occupants can see who is outside without opening the door. On a fire door, particularly a flat entrance door, it should be a fire-rated viewer covered by the door's test evidence, fitted in a correctly sized hole so it does not create a weak point.
Doorset: A doorset is a complete door assembly, usually including the leaf, frame, hinges, seals and often the closer and lock, that has been tested and is supplied together as one unit. Because every component has been proven to work together, a doorset gives a more predictable result and a clearer evidence trail than assembling a leaf, frame and hardware from different sources on site.
Drop seal: A drop seal is an automatic seal set into or onto the bottom of a door leaf that lowers to close the threshold gap as the door shuts, then lifts when it opens. Drop seals are used for smoke control and acoustic performance where a tight threshold gap is impractical. On a fire door, the drop seal must be compatible with the door's test evidence.
E30 and EI30: E30 and EI30 are European fire resistance classifications given under BS EN 13501-2 from testing to BS EN 1634-1. E30 means at least 30 minutes' integrity. EI30 means at least 30 minutes of both integrity and insulation, so the unexposed face also stays below set temperature limits. Most UK guidance for doors specifies integrity only, with insulation needed only in particular situations. The same pattern applies to E60 and EI60.
Emergency exit hardware: Emergency exit hardware is exit hardware, such as a lever handle or push pad, designed to release a door quickly in an emergency. It is classified to BS EN 179 and is intended for exits used by people who know the building and have been trained in the escape procedure, such as staff in areas not open to the public.
FD20: FD20 is a fire door rating meaning the door achieved at least 20 minutes' integrity when tested to BS 476-22. It appears in building regulations guidance mainly for some doors within dwellings, such as doors onto a protected stair in a house or a protected hallway in a flat. In practice FD30 doors are far more widely supplied, so many specifiers fit FD30 even where FD20 is the stated minimum.
FD30: FD30 is a fire door rating meaning the door achieved at least 30 minutes' integrity when tested to BS 476-22, holding back flames and hot gases for that period. It is the most common rating for doors on escape routes in flats, houses in multiple occupation, offices and schools. The European equivalent integrity classification is E30, tested to BS EN 1634-1.
FD30S: FD30S describes an FD30 fire door that also restricts the passage of smoke at ambient temperature, shown by the suffix S. The smoke performance comes from testing to BS 476-31.1, usually achieved with smoke seals in the frame or leaf edges. FD30S is the usual specification for flat entrance doors and many communal doors, because cold smoke can make an escape route unusable long before flames arrive.
FD60: FD60 is a fire door rating meaning the door achieved at least 60 minutes' integrity when tested to BS 476-22. It is typically specified where a door sits in a wall with higher fire resistance, such as some compartment walls, protected shafts, plant rooms and parts of taller buildings. The European equivalent integrity classification is E60, tested to BS EN 1634-1.
Fire door hinge: A fire door hinge is a load-bearing hinge suitable for use on fire doors, typically classified to BS EN 1935, with grade 13 commonly specified. Fire doors are usually hung on at least three hinges made from a high melting point material such as steel, positioned as the test evidence requires. Worn, loose or missing hinge screws are a frequent cause of dropped, poorly closing doors.
Fire door inspection: A fire door inspection is a systematic check of a fire door's condition and installation against its evidence and current guidance. It covers the leaf, frame, gaps, seals, hinges, closer, latch, glazing, signage and fire stopping, and records whether the door passes, needs repair or needs replacement. Frequency depends on use and risk, and some residential buildings in England have legal minimums.
Fire door signage: Fire door signage is the mandatory safety signage fixed to fire doors to tell people how to treat them, typically white text on a blue circular or rectangular background. Common messages include keep shut on self-closing doors, keep locked on cupboard and riser doors, and keep clear on doors held open by automatic devices. Signs are usually fixed at eye level on each relevant face.
Fire stopping: Fire stopping is the sealing of gaps and openings in fire-resisting construction, using tested materials, so fire and smoke cannot bypass it. Around a fire door, it means sealing the gap between frame and wall with products that have evidence for that use. General-purpose expanding foam or loose timber packers are not acceptable unless the product has test evidence for that application.
Fire-rated glass: Fire-rated glass is glazing tested to remain in place and resist fire for a stated time when installed in a tested system. Some types provide integrity only; others, usually laminated with intumescent interlayers, also provide insulation. Ordinary float or toughened glass is not fire-rated. The glass must be compatible with the door, beads and glazing seals named in the door's test evidence.
Fire-rated letterplate: A fire-rated letterplate is a letter opening tested for use in a fire door, typically with an intumescent liner or flap that closes the aperture when heated. It is fitted mainly to flat entrance doors. Cutting a standard letterplate into a fire door, or fitting any letterplate the door's evidence does not cover, can undermine the door's fire and smoke performance.
Flat entrance door: A flat entrance door is the front door between an individual flat and the common parts of a block, such as a corridor, lobby or stair. Because it protects the shared escape route, it is normally a self-closing fire door, commonly FD30S. Whether the freeholder or leaseholder owns and maintains it depends on the lease, although both have an interest in it working.
Free-swing closer: A free-swing closer is an electrically powered closer that lets a door move freely, as if no closer were fitted, during normal use. When the fire alarm sounds or the power fails, the device releases and the door closes under its own spring. Free-swing closers to BS EN 1155 suit care homes and other settings where residents struggle with heavy doors.
Glazing bead: A glazing bead is the timber or metal section that holds glass in place within a door aperture. In a fire door, the bead's profile, material and fixing method, such as the type and spacing of pins or screws, form part of the tested glazing system, usually alongside intumescent glazing seals. Replacing beads with a non-tested profile can undermine the door's fire resistance.
Higher-risk building: A higher-risk building, in England, is a building at least 18 metres tall or with at least seven storeys that contains two or more residential units, under the Building Safety Act 2022 regime. Accountable persons must register these buildings with the Building Safety Regulator, which acts as their building control authority, and manage building safety risks, including fire doors, on an ongoing basis.
Hold-open device: A hold-open device is an electrically powered unit, such as a wall or floor magnet or a closer with an electromagnetic hold-open, that keeps a fire door open in normal use and releases it when the fire alarm sounds or the power fails. Devices for fire doors are covered by BS EN 1155. Wedges, hooks and furniture are never acceptable substitutes.
Insulation: Insulation, in fire resistance testing, is the ability of a door or element to limit the temperature rise on the side away from the fire for a stated time. It is shown by the letter I in European classifications such as EI30. Most fire doors in UK buildings are specified for integrity only, but insulation may be needed where combustible materials or people could be close to the unexposed face.
Integrity: Integrity is the ability of a fire-resisting door or element to stop flames and hot gases passing through it, or appearing on the side away from the fire, for a stated time. It is the core measure behind FD ratings and the E in European classifications. In a test, integrity fails when gaps open beyond set sizes, sustained flaming appears on the unexposed face, or hot gases ignite a cotton pad held against it.
Intumescent pads and liners: Intumescent pads and liners are thin sheets of heat-reactive material fitted behind or around hardware that is cut into a fire door, such as hinge blades, lock bodies, keeps and letterplates. When heated they expand to fill the voids created by those cut-outs, helping to maintain the door's fire resistance. Hardware manufacturers and door evidence normally specify where they are needed.
Intumescent strip: An intumescent strip is a seal fitted in a groove in the door frame or leaf edge that swells rapidly when heated, closing the gap between leaf and frame to block flames and hot gases. Many are combined seals, with a brush or fin that also restricts cold smoke. The size, type and position of strips must match the door's test evidence.
LACORS guidance: LACORS guidance, formally Housing – Fire Safety, is guidance on fire safety in certain types of existing housing produced by the former Local Authorities Coordinators of Regulatory Services. Councils commonly use it to assess fire precautions in houses in multiple occupation and some flats, including where fire doors and self-closers are needed. It is guidance rather than law, but councils often rely on it.
Leaf-to-frame gap: The leaf-to-frame gap is the clearance between the edges of a door leaf and its frame along the hinge side, lock side and head. On a fire door it is typically a few millimetres and must fall within the range set by the door's test evidence. Gaps that are too wide or uneven can let smoke and flames through before the intumescent seal activates.
Lipping: A lipping is a strip of hardwood or other material bonded to the vertical edges of a fire door leaf to protect the core and provide a solid edge for hinges, locks and seals. Lipping thickness limits how much a fire door can be trimmed on site, because cutting through or too close to the core can compromise the door's fire performance.
Opening force: Opening force is the effort needed at the leading edge of a door to open it. Approved Document M guidance is not more than 30 newtons from 0 to 30 degrees and not more than 22.5 newtons from 30 to 60 degrees. Heavy closers on fire doors often exceed these figures, so closer choice and adjustment, or alarm-linked devices, are important where accessibility matters.
Overhead door closer: An overhead door closer is a surface-mounted closer, fixed to the leaf or frame head, that uses a spring and hydraulic damping to close the door in a controlled way. Closers for fire doors are classified to BS EN 1154 and must be suitable for fire door use. Adjustable closing speed, backcheck and latching action, a final boost that pushes the leaf past seal resistance onto its latch, let the installer balance reliable closing against ease of opening.
Panic hardware: Panic hardware is exit hardware, usually a horizontal push bar across the width of the door, that releases the door when pressed anywhere along its length. It is classified to BS EN 1125 and is intended for exits used by people who may be unfamiliar with the building or the hardware, such as members of the public, visitors and customers.
Protected route: A protected route is an escape route enclosed in fire-resisting construction, such as a protected stair, protected corridor or protected lobby, so people can travel along it to a final exit or place of relative safety. The fire doors opening onto a protected route, including flat entrance doors and stair doors, are what keep fire and smoke out of it.
Rebate and stop: A rebate is the recess in a door frame, formed by a raised stop, that the leaf closes against. The stop may be machined from solid timber or planted on as a separate strip. On fire doors, the rebate depth and stop arrangement form part of the tested design, and the leaf must sit evenly against the stop so intumescent strips and smoke seals can work as intended.
Regulation 10: Regulation 10 of the Fire Safety (England) Regulations 2022 requires the responsible person in residential buildings above 11 metres to check communal fire doors at least every three months and to use best endeavours to check flat entrance doors at least every 12 months. It applies in England only. Records of each check, including attempts to gain access to flats, help demonstrate compliance.
Remedial works: Remedial works are the repairs, adjustments and replacements carried out to put right defects found in a fire door inspection or fire risk assessment. Typical items include adjusting or replacing closers, renewing intumescent strips and smoke seals, correcting gaps, refixing hinges, fire stopping around frames, and replacing doors that cannot be repaired within their evidence. Each item should be recorded against the original finding.
Responsible person: The responsible person is the person with legal duties for fire safety in premises under the Regulatory Reform (Fire Safety) Order 2005 in England and Wales. It is usually the employer, or the owner or person in control of the premises, such as a landlord or managing agent. Duties include fire risk assessment and maintaining fire doors. Scotland and Northern Ireland use their own legislation and terms.
Riser door: A riser door is an access door to a vertical service shaft carrying pipes, cables or ducts between floors. Because a shaft can spread fire and smoke between storeys, the door is normally fire-rated to suit the shaft enclosure and fire stopped around its frame. Riser doors kept locked shut often do not need self-closers but should carry keep locked signage.
Scottish Technical Handbooks: The Scottish Technical Handbooks are the guidance documents supporting the Building (Scotland) Regulations 2004, published as separate domestic and non-domestic handbooks. Section 2 covers fire, including compartmentation, escape routes and fire doors. In occupied non-domestic premises, fire safety duties arise separately under the Fire (Scotland) Act 2005, so new work and ongoing management follow different rules.
Section 20 consultation: Section 20 consultation is the statutory process under the Landlord and Tenant Act 1985 that landlords in England and Wales must follow before carrying out qualifying works where any leaseholder would contribute more than £250. It involves formal notices, estimates and time for leaseholder observations. Skipping it can limit what the landlord recovers, so it must be built into fire door replacement programmes.
Self-closing device: A self-closing device is any mechanism that closes a door automatically from any open position and engages its latch, such as an overhead closer, concealed closer or a free-swing closer that activates on alarm. Most fire doors on escape routes must be self-closing, because an open fire door gives no protection. Doors to cupboards and risers kept locked shut are a common exception.
Smoke control classification: Smoke control classification describes how well a door restricts smoke leakage. Under BS EN 13501-2, a door that meets the ambient temperature leakage limits when tested to BS EN 1634-3 is classified Sa. A more demanding classification, S200, also covers leakage at medium temperature, the condition often referred to as Sm. The older British equivalent is the S suffix from BS 476-31.1, as in FD30S.
Smoke seal: A smoke seal is a flexible brush, fin or blade seal fitted around the edges of a door to restrict cold smoke leaking past it at normal temperatures, before any intumescent material reacts. Smoke seals give a door its S or Sa smoke control performance. They are easily damaged or painted over, so they are among the first items checked during a fire door inspection.
Technical Booklet E: Technical Booklet E is the guidance on fire safety supporting the Building Regulations (Northern Ireland) 2012. It plays a similar role to Approved Document B in England and Wales, describing ways of meeting the fire safety requirements for new work, including where fire doors are needed. Fire safety in occupied premises in Northern Ireland is governed separately, under the Fire and Rescue Services (NI) Order 2006.
Third-party certification: Third-party certification is independent verification by an accredited certification body that a fire door product is made consistently to its tested design, or that an installer works to a defined standard. It involves audits and ongoing checks. Schemes commonly seen include BWF Certifire, BM TRADA Q-Mark, FIRAS and IFC Certification, covering door manufacture, installation or both.
Threshold gap: The threshold gap is the space between the bottom edge of a door leaf and the floor or threshold beneath it. The threshold is the floor-level strip or plate across the base of the opening. On fire doors, the permitted gap is set by the door's test evidence and installation guidance, and doors needing smoke control generally require a much tighter gap or a drop seal.
Vision panel: A vision panel is a glazed opening in a door leaf that lets people see through before opening the door, reducing collisions and helping supervision. In a fire door, the glass, beads, glazing seals and fixings must form a tested glazing system, and the size and position of the aperture must stay within the limits of the door's test evidence.

Fire door glossary

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