Document - London Building Control

Loft Conversions - The building regulations Chris Wigley MD London Building Control Ltd www.londonbuildingcontrol.co.uk

Scheme 1: Bungalow with Loft Conversion

Scheme 1: Bungalow with Loft Conversion 

Option 1A: Means of escape from first floor windows •

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Means of escape windows to all first floor habitable rooms (minimum 450mm wide, with opening of 0.33m2) Interlinked mains SD to halls/landings

Option 1B: Protected route • •

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with enclosed staircase leading to final exit FD20 doorsets to habitable rooms including kitchens and rooms with boilers Interlinked mains SD to halls/landings

Scheme 2: Two Storey house with Loft Conversion

Scheme 2: Two Storey house with Loft Conversion

Scheme 2: Two Storey house with Loft Conversion 

Option 2A: A protected route • • •

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Two Storey house with Loft Conversion (Lounge open to stairs) As Option 2A: Re-instate a protected route •

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with enclosed staircase leading to final exit FD20 doorsets to habitable rooms including kitchens and rooms with boilers Interlinked mains SD to halls/landings

Form route using 30 minute FR construction (FD20 doorsets) or fire-curtains

Option 2B: Sprinklers • • • •

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Sprinklers to Ground Floor rooms FD20 doorsets/construction to separate the Ground Floor from the First Floor MOE from a First Floor room to a place of safety First Floor doors to be FD20 or upgraded using envirograf or similar New doors to the loft to be FD20

Scheme 3: Three Storey house with Loft Conversion

Scheme 3: Three Storey house with Loft Conversion 

Option 3A: Protected route and smoke detection throughout • •

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Protected route to final exit FD20 doorsets throughout SD throughout (HD in kitchen) No open plan arrangements allowed

Scheme 4: Two Storey building (flats) with Loft Conversion 

Option 4A: Independent access •

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Treat as Two Storey house with Loft Conversion (Scheme A)

Option 4B: Creation of maisonette •

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Protected internal stairs to a flat exit FD20 doorsets throughout SD throughout (HD in kitchen)

Scheme 5: Three Storey building (flats) with Loft Conversion 

Option 5A: Independent access •

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Treat as Three Storey house with Loft Conversion (Scheme C)

Option 5B: Creation of maisonette at a high level (over 7.5m above Ground Level) • • •

Protected internal stairs to a flat exit SD & FD20 doorsets throughout Secondary escape route/stairs required, or a fire engineered solution

Guidance based upon LABC Technical Guidance Note 

This guidance is intended for two storey houses that are converted to form 3 storeys.

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The new 3rd storey floor area should not exceed 50m².

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Existing hardboard or other lightweight (hollow-core) doors are not considered adequate to provide a reasonable level of fire protection to a stair enclosure and should therefore be replaced with FD 20 doors.

Option 1: Upgrading existing doors (minimum 32mm thick) 

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Detection throughout: smoke detectors should be provided in all habitable rooms, at every storey level (including any half landing levels adjacent to habitable rooms) with a HD in the kitchen. All alarms should be mains powered with battery backup, and interlinked. BS 5839:6 recommends optical detectors in circulation areas with ionization detectors for living/dining rooms. Either type is acceptable in bedrooms. There should be at least one window at first floor level of a size that would permit emergency egress to either a rear garden of sufficient depth (i.e. at least as deep as the rear elevation’s height) or from the front elevation, leading to a place of safety (i.e. not over light wells) The door should be attached to the door frame with steel hinges, not be visibly warped, fit well into its frame and there should be no visible defects particularly in the panels. Any existing glazing to doors or fanlights should be replaced by wired glass or similar fire resistant glazing to provide adequate resistance for integrity and stability. There should be no significant defects to adjacent walls or around door frames forming the stair enclosure.

Option 2: Upgrading existing doors (less than 32mm thick) 

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Detection throughout: smoke detectors should be provided in all habitable rooms, at every storey level (including any half landing levels adjacent to habitable rooms) with a HD in the kitchen. All alarms should be mains powered with battery backup, and interlinked. BS 5839:6 recommends optical detectors in circulation areas with ionization detectors for living/dining rooms. Either type is acceptable in bedrooms. There should be at least one window at first floor level of a size that would permit emergency egress to either a rear garden of sufficient depth (i.e. at least as deep as the rear elevation’s height) or from the front elevation, leading to a place of safety (i.e. not over light wells) The door should be attached to the door frame with steel hinges, not be visibly warped, fit well into its frame and there should be no visible defects particularly in the panels. Any existing glazing to doors or fanlights should be replaced by wired glass or similar fire resistant glazing to provide adequate resistance for integrity and stability. There should be no significant defects to adjacent walls or around door frames forming the stair enclosure. A proprietary solution should be sought to upgrade the door; this may include the application of fire resistant materials to the panels and stiles on the room side of the door. Such doors can be provided with a certificate from a specialist supplier confirming their upgraded suitability. Alternatively the door can be upgraded, on the room side, by infilling the panel with a fire resistant board and applying a similar board glued and screwed over the entire door.

General Notes for all Options  

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G1). Smoke Detectors can use a wireless link (if certification is provided). G2). FD20 doorsets (not FD30 doors) are usually required in Loft Conversions; smoke seals are not required. Intumescent strips are also not usually required as fire doors are manufactured to provide 20 minutes FR without these strips -intumescent strips are used to increase FR to 30 minutes, when this is required. 50mm thick doorstops are also not usually required within dwellings as it is now accepted practice to allow smoke to seep out and set off the detectors in the halls/landings. G3). In a house, the top floor may have an open plan arrangement (ie. no door onto the stairs). However this is not permitted in maisonettes (where an inner protected hall is needed). G4). Each scheme will need an individual survey to ensure there are no unusual site conditions. G5). Steels supporting floors/walls will need 30 minutes FR. Protection from the underside is sufficient; the plasterboard needs to be at least 12.5mm thick fireline board or similar – otherwise steels can be painted with intumescent paint. G6). Where an older house/flat has low headroom, the new Loft Room floor may be under 4.5m above the adjacent Ground Level. The provision then is only for SD’s in halls/landings and an adequate MOE window from each new habitable room.

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