Part B of the Building Regulations deals with fire safety, covering matters such as means of escape, fire spread, structural fire resistance, and access for the fire service. It applies to new buildings, extensions and material alterations, with particular importance for multi-storey buildings and buildings close to boundaries.
Part B of the Second Schedule to the Building Regulations covers fire safety, requiring that a building be designed and constructed so that, in the event of fire, occupants can escape safely, fire and smoke spread is limited, the structure retains adequate stability for a reasonable period, and the fire service has reasonable access to fight the fire. Technical Guidance Document B sets out detailed guidance on achieving these objectives, covering matters like means of escape, compartmentation, fire-resisting construction, and external fire spread between buildings.
For many buildings, particularly larger, multi-storey, or non-domestic buildings, a fire safety certificate must be obtained from the local authority Building Control Section before construction begins, confirming that the proposed design complies with the fire safety requirements of Part B. Certain smaller domestic works, such as many single-storey house extensions, are often exempt from the fire safety certificate requirement, but the underlying obligation to comply with Part B itself still applies regardless of whether a certificate is formally required.
Fire safety considerations are also particularly relevant where a building or extension is close to a boundary, since fire spread risk to neighbouring property is a key concern addressed through requirements on external walls, roof coverings and separation distances. This is a common issue for extensions built near boundaries and should be addressed early in design.