What is Approved Document B?

Approved Document B (ADB) sets out guidance for meeting the fire safety requirements of Part B of Schedule 1 to the Building Regulations 2010 in England. It covers means of escape, spread of fire, and access and facilities for the fire service. Volume 1 covers dwellinghouses; Volume 2 covers all other buildings.

How does Approved Document B relate to BS EN 12101?

Approved Document B references the BS EN 12101 series as the technical standard for smoke control systems. Where ADB requires smoke ventilation, the components and systems used must comply with the relevant parts of BS EN 12101. ADB sets the scenario and outcome; BS EN 12101 defines how components must perform.

When does Approved Document B apply to smoke ventilation?

ADB requires smoke ventilation in buildings where escape routes could become untenable during a fire: primarily common areas in blocks of flats (above 11 metres or in mixed-use buildings), commercial premises, and buildings where the fire strategy relies on smoke control for occupant safety.

Does Approved Document B apply in Scotland and Wales?

No. Approved Document B applies in England only. Scotland uses the Technical Handbooks (Domestic and Non-Domestic), and Wales uses the Welsh Government's Approved Documents. The technical requirements for smoke ventilation are broadly similar but differ in specific details, and specifiers must reference the correct document for the location of the project.

BS EN 12101 and Approved Document B

BS EN 12101 is recognised in Approved Document B (Fire Safety) as the technical benchmark for designing and commissioning smoke control systems. While Approved Document B describes what a building must achieve, BS EN 12101 provides the detailed specifications for how to achieve it.

Part of the BS EN 12101 standard family.

Key Alignment Points

Life-Safety Intent

Both BS EN 12101 and Approved Document B prioritise the safe evacuation of occupants. Every requirement in BS EN 12101 - from the thermal classification of AOV windows to the fire performance of dampers to the emergency power supply - serves this central purpose.

Competence and Certification

Approved Document B increasingly emphasises the need for competent design, installation, and commissioning. BS EN 12101 provides the technical framework against which competence is judged. A specifier, installer, or commissioning engineer who understands BS EN 12101 demonstrates the competence required to deliver life-safety systems.

Building Control Sign-Off

Building control bodies expect every smoke control system to be designed, installed, and commissioned in accordance with BS EN 12101. This is a non-negotiable requirement for obtaining completion certificates.

The Building Safety Act 2022 and the Golden Thread

The Building Safety Act 2022 introduced the concept of the golden thread - a continuous record of all design decisions, building regulations compliance, and ongoing maintenance for higher-risk buildings. Smoke control systems are explicitly included.

What the Golden Thread Requires

Design Stage - Every decision regarding AOV selection, fan sizing, damper specification, and control logic must be documented and traceable.

Installation Stage - Every product installed must be verified against the design specification, with site records and photographs proving compliance.

Commissioning Stage - Every system must be tested and a commissioning certificate issued, signed by a competent engineer, confirming it meets BS EN 12101.

Handover Stage - Complete documentation - schematic diagrams, cause-and-effect tables, commissioning records, maintenance procedures - must be provided to the responsible person.

In-Service Stage - The building operator must maintain records of all scheduled maintenance, inspections, and faults discovered and rectified.

The golden thread is increasingly subject to audit by building control, fire safety regulators, and insurers. Non-compliance can result in enforcement action and criminal liability under the Building Safety Act.

Compliance for Specifiers

Determine the smoke control strategy - passive systems, active extraction, or a combination - based on building layout, occupancy, and fire risk
Reference BS EN 12101 in the specification - every product must explicitly reference the relevant part (e.g. “all roof vents shall comply with BS EN 12101-2”)
Select certified products - all major components must have third-party CE certification; retain Declarations of Performance
Provide design documentation - schematic diagrams, performance calculations (use the Free Area Calculator for corridor and stair Aa sizing), and a cause-and-effect table
Engage building control early - submit the smoke control specification at design stage to agree the approach

Compliance for Contractors

Verify compliance before installation - confirm products match specification and carry required certifications
Install to standard - follow manufacturer instructions and BS EN 12101 best practice for mounting, wiring, and override provisions
Quality assurance - conduct on-site inspections, document any deviations, resolve before handover
Prepare for commissioning - confirm all components functional, control logic programmed, manual overrides operational

Compliance for Commissioning Engineers

Test each component - every AOV, damper, fan, and control function; document all results
Verify control logic - activate fire alarm signals and confirm every safety function operates in correct sequence
Test emergency power - simulate mains failure and confirm emergency supply activates and critical functions continue
Sign the commissioning certificate - issued by a competent engineer confirming the system meets BS EN 12101
Provide training and documentation - ensure building operators understand manual overrides and maintenance requirements

Vent Trade and Golden Thread Compliance

Vent Trade retains complete documentation for every project - product certificates, installation records, commissioning certificates, and maintenance schedules - supporting the golden thread requirements of the Building Safety Act.

Our commissioning service and CPD training are designed to ensure every engineer involved in smoke control understands BS EN 12101 and can deliver systems that protect occupants and satisfy building control.

Contact our engineering team to discuss your project.

BS EN 12101-2 - AOVs and smoke exhaust ventilators
BS EN 12101-3 - Powered extract fans
BS EN 12101-6 - Pressure differential systems
BS EN 12101-8 - Smoke dampers
BS EN 12101-10 - Emergency power supplies

Back to BS EN 12101 Overview

BS EN 12101 and Approved Document B: The UK Regulatory Context