Fire Safety Regulations for London Homes 2025: What Homeowners and Landlords Must Know

Building Regulations Part B sets the technical standards for fire safety that must be met whenever a new building is erected or when certain types of alteration work are carried out on an existing building that requires Building Regulations approval. Part B applies to: new dwellings (including new build houses, flats, and residential conversions); extensions of existing dwellings (rear extensions, loft conversions, garage conversions, side extensions); certain internal alterations that create new habitable rooms, change means of escape, or affect fire compartmentation. The key Part B standards for London residential properties: Means of escape (Part B1): every habitable room must have a means of escape in case of fire. For ground floor rooms in a single-family house with an openable window, the window itself can be the means of escape (window minimum clear opening of 0.33 sq m, minimum dimension of 450mm, maximum sill height above floor of 1,100mm). For upper floor rooms (first floor and above), a protected escape route (hallway and staircase forming a protected corridor) must be provided. For loft conversions creating a new habitable room on a second or third floor, a protected staircase with fire-resisting enclosure (30-minute fire resisting walls and ceiling, self-closing fire doors) is typically required if the total floor level of the habitable room is more than 4.5m above ground level. Internal fire spread (linings) (Part B2): wall and ceiling linings in escape routes must achieve the appropriate Class 0 or Class 1 surface spread of flame classification. Internal fire spread (structure) (Part B3): the fire resistance period for structural elements (walls, floors, beams, columns) depends on the building height and use class. For a typical London two-storey terrace: 30 minutes fire resistance for elements separating floors (first floor joists, ceiling plasterboard below). For a building of three or more storeys: 60 minutes for elements at or below the first floor level. Party wall fire compartmentation (Part B3): the party wall separating a semi-detached or terraced property must provide adequate fire compartmentation — in practice, the party wall between two London Victorian terrace properties typically provides adequate compartmentation through its mass (9-inch solid brick or cavity construction). However: any new opening made through a party wall (for a through-wall beam, a pipe penetration, or a chimney breast removal where the party wall is disturbed) must be fire-stopped. Fire detection and alarms (Part B1/Part B6 of AD B): for a new loft conversion or extension creating a new room, smoke alarms interconnected with the existing alarm system are required. For a building of three or more storeys with a loft conversion, the alarm standard is typically a Grade D, Category LD2 system (mains-powered, interlinked smoke alarms at each landing, each floor level, within 3m of the bedroom door on the escape route, and a heat alarm in the kitchen). For an existing two-storey house without any new work: no Building Regulations requirement to upgrade fire alarms (though the private rented sector has separate statutory requirements under the 2015/2022 Regulations — see below).

Fire doors (FD30 — 30-minute fire resistance, typically with a self-closing device and intumescent strips and cold smoke seals) are required in specific locations determined by Building Regulations Part B when building work is carried out: Loft conversions in London: when a loft conversion creates a new habitable room or rooms on a floor level at or above 4.5m above ground level, a fire door (FD30S — 30 minutes fire resistance, with cold smoke seal) is required: at the door from each habitable room opening onto the protected staircase enclosure; at the door between the protected staircase and the kitchen (a kitchen fire is a common fire origin, and the kitchen door opening onto the escape staircase must be fire-resisting). In a typical two-to-three storey London Victorian terrace with a loft conversion: fire doors are required at: the new loft room door (at the bottom of the loft stair, opening onto the second floor landing); the kitchen door (ground floor, opening onto the hallway/staircase escape route); and often all other doors opening directly onto the protected staircase escape route. Extensions: where an extension alters the means of escape or creates a new inner room (a room with only one exit, through another room, rather than directly onto an escape route), fire doors or other compensating measures may be required. Garages (integral and attached): when a garage is converted to a habitable room, a fire door (FD30S) is required at the connection between the converted garage and the dwelling — the garage is treated as a higher fire risk area. When a garage (integral, sharing a wall with the house) remains as a garage (not converted to habitable use): if the party wall between the garage and the house has not been upgraded, a fire-resisting door and frame (FD30S) should be provided at the connection between the garage and the dwelling. HMOs (Houses in Multiple Occupation): HMOs are subject to significantly more rigorous fire safety requirements than single family dwellings. The fire safety requirements for HMOs are set by: the Licensing Authority (the London borough), which sets fire safety conditions as part of the HMO licence; the Housing Act 2004 (Housing Health and Safety Rating System — HHSRS) which includes a fire hazard assessment; and the Regulatory Reform (Fire Safety) Order 2005 (RRO) which applies to the common parts of an HMO. For a typical London three-to-five bedroom HMO: fire doors (FD30S) are required at all room doors opening onto the common escape route (hallway and staircase); at the kitchen door; at the door to any cupboard under the stair (the staircase void is a fire risk). Thumb-turn locks (allowing escape from inside without a key) are required on fire doors on the escape route. Intumescent strips and cold smoke seals are required on all fire doors. Self-closing devices (spring hinges or overhead closers) on all fire doors. FD30 cost in London: supply and installation (door set, frame, intumescent strips, cold smoke seal, self-closer): £400-£900 per door set, depending on specification (solid core timber, glazed, or solid composite). A new fire door installation through a dividing wall: £600-£1,200 per door including making good.

The Smoke and Carbon Monoxide Alarm (England) Regulations 2015 (as amended by the 2022 Regulations) impose statutory obligations on private rented sector (PRS) landlords in London: Smoke alarms: at least one smoke alarm must be installed on each storey of the property where there is a room used wholly or partly as living accommodation (this includes a landing — any floor level with a room used for living must have a smoke alarm on that floor). Carbon monoxide alarms: a carbon monoxide (CO) alarm must be installed in any room used wholly or partly as living accommodation where a fixed combustion appliance (other than a gas cooker) is present. Fixed combustion appliances include: gas boiler (boiler cupboard is living accommodation in the relevant sense — CO alarm required); solid fuel fire (log burner, open fire); gas fire. Oil boiler. Note: a gas cooker in the kitchen is specifically excluded from the CO alarm requirement, but any other gas appliance (gas hob without an oven or with an oven, a gas fire, a gas boiler) requires a CO alarm in the same room. Landlord testing obligation: landlords must ensure smoke and CO alarms are in working order at the start of each new tenancy. The duty to test is the landlord's (or their agent's) at the start of each tenancy — tenants then have a duty to maintain the alarms and notify the landlord of any fault. Alarm types: the Regulations do not specify a particular type of alarm (mains-powered or battery-powered, Grade D or otherwise) for PRS properties — but best practice (and good practice guidance from LACORS and NFCC) recommends: mains-powered, interlinked smoke alarms with tamper-proof battery backup (Grade D, LD2 as a minimum) for any property with three or more storeys or an HMO. For a simple two-bedroom, two-storey terrace: optical smoke alarm on the ground floor landing, optical smoke alarm on the first floor landing, and a CO alarm in the boiler cupboard is a common minimum compliant installation. Enforcement: the Local Authority can serve a remedial notice on a non-compliant landlord requiring compliance within 28 days. Failure to comply: the LA can arrange for the alarms to be installed and charge the cost to the landlord. Penalty: up to £5,000 for a breach of the CO alarm Regulations (from 2022). Landlords and agents should ensure compliance is checked and documented at the start of every new tenancy.