Definition
Approved Document B
Approved Document B is the UK Building Regulations guidance document covering fire safety in the design and construction of new buildings and major extensions. It sets requirements for means of escape, internal fire spread, compartmentation, external fire spread, and access for the fire and rescue service, and references British Standards — including BS 5839 and BS 5266 — for specific technical requirements.
Terms mentioned in this definition
Relevant UK Standards & Legislation
- Building Regulations 2010 (Part B)The regulations that Approved Document B provides guidance for meeting
- BS 5839-1:2017Referenced by Approved Document B for fire detection and alarm systems
- BS 5266-1:2016Referenced by Approved Document B for emergency lighting requirements
- BS 9999:2017Alternative compliance route to Approved Document B for fire safety in buildings
Related Terms
- Regulatory Reform (Fire Safety) Order 2005Fire Regulations & StandardsThe Regulatory Reform (Fire Safety) Order 2005 (RRO) is the primary fire safety legislation in England and Wales, applying to all non-domestic premises. It places a legal duty on the responsible person to carry out a fire risk assessment, implement appropriate fire safety measures, and maintain them effectively. Non-compliance can result in unlimited fines or imprisonment of up to two years.View definition
- CompartmentationPassive Fire ProtectionCompartmentation is the division of a building into fire-resisting cells using walls, floors, ceilings, and fire doors, designed to contain a fire within its compartment of origin for a specified period — typically 30 or 60 minutes. It is a core element of passive fire protection and is required in all non-domestic premises under Approved Document B and assessed through every fire risk assessment.View definition
- Means of EscapeGeneral Fire SafetyMeans of escape are the designated routes — corridors, stairways, emergency exits, and final exit doors — by which building occupants can evacuate safely in a fire without obstruction. Adequate means of escape must be provided in all non-domestic premises under Approved Document B and the Regulatory Reform (Fire Safety) Order 2005, and must be identified and assessed in the fire risk assessment.View definition
- Emergency LightingEmergency LightingEmergency lighting is a lighting system that activates automatically on failure of the normal mains supply, providing sufficient illumination to enable safe evacuation of a building. UK law requires emergency lighting in all non-domestic premises, and it must be designed, installed, commissioned, and maintained in accordance with BS 5266-1 by a competent person.View definition
- BS 5839Fire Regulations & StandardsBS 5839 is the British Standard covering the design, installation, commissioning, and maintenance of fire detection and alarm systems in the UK. It is published by the British Standards Institution (BSI) and is divided into multiple parts, each covering specific building types or system components.View definition
Frequently Asked Questions
Approved Document B is the UK Building Regulations guidance document covering fire safety in the design and construction of new buildings and major extensions. It sets requirements for means of escape, internal fire spread, compartmentation, external fire spread, and access for the fire and rescue service, and references British Standards — including BS 5839 and BS 5266 — for specific technical requirements.
Requirements for approved document b in the UK depend on the type of premises and applicable legislation, including the Regulatory Reform (Fire Safety) Order 2005 and relevant British Standards. The responsible person for a premises must ensure adequate fire safety provisions are in place. The British Fire Consortium can provide guidance — contact our team or search our member directory to find a qualified specialist.
Approved Document B and Regulatory Reform (Fire Safety) Order 2005 are related fire safety concepts but serve different purposes. See our individual glossary entries for detailed definitions. For expert guidance on which applies to your premises, consult a BFC member company.
The British Fire Consortium offers EAL Level 3 accredited training covering fire safety systems including topics related to approved document b. Our courses are the only nationally recognised Level 3 qualifications across all fire disciplines. View our training courses or use the member directory to find a qualified trainer near you.