Approved Document B Consultation 2026: What Fire Safety Professionals Need to Know

A landmark review of fire safety building regulations

The Building Safety Regulator, working alongside the Health and Safety Executive and the Ministry of Housing, Communities and Local Government, has published a comprehensive review of Approved Document B (ADB), the statutory guidance underpinning fire safety in building design across England.

The consultation opened on 25 March 2026 and runs for 14 weeks, closing on 1 July 2026. All proposed changes carry a target implementation date of 2 September 2029, when a fully revised edition of ADB will come into effect.

The government estimates the proposals will carry a cumulative cost of £199 million over a ten-year period, with an estimated net annual cost to business of £29 million per year. For individual building projects, the impact is expected to be modest, typically adding between 0.1% and 0.2% to total build costs.

Seven areas of change

The consultation addresses seven distinct areas of ADB. Each carries its own set of proposed amendments, cost estimates, and consultation questions.

1. External walls and balconies

The most visible changes concern external wall systems. The consultation proposes revised guidance on fire spread over external walls across all building heights, updates to balcony fire safety provisions, and a review of the scope of the ban on combustible materials in and on external walls.

A new exemption is proposed for laminated glass products with a total thickness of more than 17.5mm but no more than 26mm, where the interlayer material has a calorific value of no more than 41 megajoules per kilogram. Several deemed-to-satisfy provisions will be removed in favour of performance-based classifications.

The estimated cost of these changes is £35 million over ten years, with approximately 67% of the impact falling on residential buildings under 11 metres.

2. Combustible structural elements

A new threshold is proposed at 11 metres for both residential and non-residential buildings. Buildings above this height that use combustible structural elements will no longer be able to rely solely on ADB guidance and will instead need to adopt a fire-engineered approach.

This threshold aligns with the consequence classes in Approved Document A and is intended to ensure that combustible structural materials receive proportionate scrutiny in taller buildings.

3. Evacuation lifts

Perhaps the most significant operational change for designers: ADB will call for a minimum of two stairs and two evacuation lifts in all new residential buildings above 18 metres. Where a firefighting lift is already provided, it may serve a dual function as an evacuation lift.

The 18-metre threshold aligns with the higher-risk building regime under the Building Safety Act 2022. The estimated cost is £31.5 million over ten years.

4. Roof fire safety and solar PV panels

The consultation introduces updated fire stopping guidance at compartment wall-to-roof junctions and, notably, new provisions for buildings with rooftop photovoltaic panel installations. The proposals include enhanced fire performance requirements for products beneath and around PV arrays, as well as limitations on panel placement near roof openings.

With the rapid growth of rooftop solar across residential and commercial buildings, this is a timely addition. The estimated cost is £28.9 million over ten years, primarily affecting flats below 11 metres.

5. Specialised housing

The term "sheltered housing" will be formally replaced with "specialised housing" throughout ADB. The guidance will distinguish between specialised housing with regulated personal care and specialised housing without personal care.

Fire alarm coverage in specialised housing with care will increase to a minimum of Category LD1 and Grade D1 per BS 5839-6:2019. The estimated cost of alarm provisions is £10.5 million over ten years, with an additional £19.2 million if a sprinkler-based alternative is adopted.

6. Open-sided car parks

Structural fire resistance ratings for open-sided car parks will increase significantly:

• Buildings between 5 metres and 18 metres: from 15 minutes to 30 minutes

• Buildings above 18 metres: from 15 minutes to 60 minutes

This is the most expensive single proposal in the consultation at £79.6 million over ten years, reflecting the structural implications for a large number of existing and planned car park buildings.

7. General clarifications

A series of smaller but important changes consolidate existing FAQ guidance into the main ADB text, clarify provisions for building work on existing buildings, and remove ambiguities identified since the last major revision. The government estimates these clarifications will carry negligible cost beyond initial familiarisation.

How to respond

The consultation includes 39 numbered questions across the seven topic areas. Responses can be submitted through three channels:

• Online survey via the HSE Citizen Space portal at consultations.hse.gov.uk/bsr/review-of-approved-document-b-fire-safety/

• Email: ADBconsultation@hse.gov.uk

• Post: Building Safety Regulator, HSE, 4th Floor, 10 South Colonnade, London E14 5EA

The full proposed text for both ADB Volume 1 (Dwellings) and Volume 2 (Buildings other than dwellings) is available on the GOV.UK consultation page.

Why this matters

Approved Document B is the foundation document for fire safety design in England. Every fire risk assessor, fire engineer, building control officer, and responsible person works within its framework. Changes to ADB ripple through the entire built environment, from the design of new residential towers to the assessment of existing commercial premises.

The 2029 implementation date gives the industry three years to prepare, but the time to shape these proposals is now. The consultation closes on 1 July 2026.

Sources: GOV.UK, Fire Protection Association, HSE Citizen Space, Salus AI