Fire Safety in Converted Buildings and Changes of Use

What This Requirement Covers

When a building undergoes a material change of use (e.g., from office to residential, warehouse to flats, or barn to dwelling), Building Regulations apply to bring the building up to current fire safety standards so far as is reasonably practicable. Regulation 6 of the Building Regulations 2010 sets out the requirements that apply on a change of use.

Key Requirements

Triggers for Fire Safety Upgrade

A material change of use triggers fire safety requirements when

1. A building becomes a dwelling or contains a flat
2. A building becomes a hotel, boarding house, or institution
3. A building becomes a public building
4. A building is altered to create additional dwellings

Minimum Standards on Conversion

1. Compartmentation: Each dwelling must be a separate fire compartment with walls and floors achieving the fire resistance appropriate to the building height
2. Means of escape: Adequate escape routes must be provided from each dwelling, complying with Approved Document B so far as is reasonably practicable
3. Fire detection: A fire detection and alarm system compliant with BS 5839-6 (Grade D1 LD2 minimum for each dwelling)
4. Fire doors: FD30S doors to protected stairways and between dwellings and common parts
5. Structural fire resistance: The structure must achieve the fire resistance period appropriate to the new use and building height

Office-to-Residential Conversions (Permitted Development)

1. Class MA of the GPDO (General Permitted Development Order) allows change of use from office (Class E) to residential (Class C3) without full planning permission
2. However, Building Regulations still apply in full, including fire safety
3. The building must be brought up to current standards for means of escape, compartmentation, and fire detection
4. A building notice or full plans application must be submitted to Building Control

Barn Conversions and Agricultural Buildings

1. Structural timber frames must be assessed for fire resistance; additional protection (fire boarding or intumescent coatings) may be required
2. Existing stone or brick walls may need upgrading to achieve the required fire resistance period
3. Compartment walls between separate dwellings must extend to the underside of the roof covering

Practical Compliance Tips

1. Commission a fire safety survey of the existing building before commencing design
2. Identify existing structural elements that may not achieve the required fire resistance and plan upgrades early
3. In multi-unit conversions, plan compartmentation and service routes to minimise fire-stopping complications
4. Consult Building Control early regarding the extent to which current standards can reasonably be applied to the existing building fabric
5. Permitted development rights for change of use do not remove the requirement for Building Regulations compliance
6. Keep detailed photographic records of all fire protection measures installed during the conversion
7. Consider appointing a fire engineer for complex conversions, particularly where the existing structure limits standard solutions