Review of Approved Document B: Fire Safety

1. Building Regulations set technical requirements covering a wide range of health, safety, access, security and sustainability issues.  

2. The Building Regulations requirements are intended to protect people’s safety, health and welfare in and around buildings. The regulations are supported by statutory guidance in ‘Approved Documents’ which provide practical guidance on ways to comply with the requirements in the regulations for many common building situations only.  

3. Approved Document B provides guidance for Part B of the Buildings Regulations, relating to fire safety.  

4. Section 14 of the Building Act 1984 requires consultation for proposed substantive changes to the Building Regulations. It has been our practice to carry out a public consultation on proposed changes to the Approved Documents, as the implications of changes can be complex and BSR believes that public consultation adds significant value. 

Grenfell Tower Inquiry Phase 2 Report Recommendations

5. In September 2024 the Grenfell Tower Inquiry published the Phase 2 Report setting out 58 recommendations for government to consider in its response to the Grenfell Tower fire. In February 2025 the government accepted all the Inquiry’s findings and committed to providing updates on progress against the recommendations on a quarterly basis.  

6. The Ministry of Housing, Communities and Local Government (MHCLG) has asked the Building Safety Regulator (BSR) to support the government’s response to recommendations 5, 7, 8, 11 and 12 relating to issues that are to be considered as part of the review of Approved Document B.   

7. Recommendation 5 of the Phase 2 report made clear that ‘the statutory guidance generally, and Approved Document B in particular, be reviewed accordingly and a revised version published as soon as possible.’  

8. This consultation will deliver on key parts of Recommendation 5, with the wider review of Approved Documents still ongoing (Membership of Fundamental Review of Building Regulations Guidance - GOV.UK) and enable a full response to recommendation 12.  

Continuous Review of Approved Document B

9. Ahead of the full government response to the Phase 2 report, the government announced in December 2024 that the Building Safety Regulator (BSR) has been instructed to keep the guidance within Approved Document B under continuous review. This is in line with BSR’s statutory duty under section 5 of the Building Safety Act 2022 to keep the safety and standards of all buildings under review.  

10. The continuous review programme brings together three core strands:  

1. Technical review: Following a 2018 call for evidence, government commissioned ten research projects covering key fire safety themes. Seven further reports from this phase of research have been published in December 2025 to support this consultation, in addition to two reports that were published in support of previous consultations 
2. Horizon scanning: BSR monitors trends to anticipate future risks and inform development of guidance. This includes the long-standing investigation of real fires programme. Running since the 1980s, this strand of research investigates fire incidents to identify patterns and inform options for changes to building regulations and future guidance. Five new research reports have been published and yearly summaries will be published going forward, with the first two published in August 2025  
3. Sector engagement: Guidance is shaped through regular dialogue with the Building Advisory Committee and its Part B Fire Safety Working Group. Each research project was and will continue to be supported by a Technical Steering Group of industry and academic experts  

11. The continuous review of Approved Document B forms a key objective of the Building Safety Regulator. This review ensures that we continuously identify areas of the guidance which either already need strengthening or will need to be strengthened in the future. This approach ensures that areas of the guidance which have not been reviewed yet, will be. This allows us to identify at the earliest opportunities how new materials and methods of construction challenge the guidance and adapt it to enable safe innovation in the construction sector. 

12. Our objective for the continuous review is to bring forward changes to the guidance at planned frequent intervals. This gives the construction industry time to engage with the review and organise their work going forward accordingly.  

13. Alongside this consultation, BSR has published further information on the scope of the continuous review. The page can be found here: Continuous review of Approved Document B - GOV.UK

Overview of Consultation

14. The government made a commitment in December 2024 for the Building Safety Regulator (BSR) to keep Approved Document B under continuous review Building on this, announced through the government's response to the Phase 2 report in February 2025, and reiterated through the government’s annual report in February 2026, BSR has now launched the consultation on further changes in March 2026. 

15. The government response recognises that the guidance in Approved Document B has been updated several times since 2017. 

16. Delivering on this commitment, BSR is now consulting on proposed options for:  

1. small but important clarifications and technical changes to the guidance within Approved Document B 

2. consolidated guidance for designing building work on existing buildings 

3. the introduction of a threshold whereby the guidance within Approved Document B should not be applied when combustible elements of structure are used 

4. revised and updated guidance on external wall systems and balconies, and review the scope of the ban on combustible materials in and on external walls 

5. new provisions for evacuation lifts in residential buildings above 18m, and clarifying the related guidance for non-residential buildings 

6. updated terminology on ‘sheltered housing’, introducing the new term ‘specialised housing’ in its place and increased provisions for detection and alarm coverage in these buildings types 

7. updated guidance on roofs including new provisions for the incorporation of photovoltaic (PV) panels 

8. increase in the fire resistance rating of open-sided car parks 

17. This consultation covers areas where sufficient evidence has been found to support the inclusion of changes in the technical review of Approved Document B. To further support this consultation, the research reports have been published in December 2025.

18. This consultation provides the opportunity to review and comment on the updated guidance text. This allows direct feedback on the wording of the changes to ensure they are clear and unambiguous. The consultation makes clear within each section where the guidance can be found, whether within the consultation document itself, through the online portal or via external links to documents.   

19. It should be noted that through the changes highlighted there is no suggestion that existing and upcoming buildings are inherently unsafe, as long as they have been built in accordance with the relevant standards at the time, are well-maintained, and properly managed.   

Combined Impact of changes

20. The Building Safety Regulator takes the impact of new standards on the construction industry very seriously. We have carried out detailed assessments of the proposals in this consultation to ensure that they are proportionate and any impact from changes to the guidance is mitigated where possible.

21. The proposed preferred options outlined in the consultation below will have a cumulative cost spread across all building types of £199 million over a 10-year period, with an estimated net annual cost to business (ENACB) of £29 million per year . Of this, the cost of familiarisation is anticipated to be £12.6 million over 10 years with an ENACB of £1.3 million per year. The specific impacts on proposed changes are outlined in each section of the consultation. 

22. Across all the changes, there are a range of benefits that will be achieved across the built environment and for residents. There are inherent challenges of quantifying benefits from improvements to building safety and at this stage the benefits have not been costed.  

23. Based on our assessment, the benefits of clarifying the guidance and greater regulatory alignment with industry and planning guidance include:  

1. Easier to design schemes leading to reductions in design time 

2. Reducing the number of schemes underproviding fire protection measures to improve the consistency in fire safety provisions across buildings 

3. Improved clarity for non-design professionals (such as the fire and rescue service, building control bodies and residents) reducing the risk of misinterpretation, improved operational clarity and potential for faster approvals 

4. Reducing the risk of future remediation due to better initial compliance and limiting post-occupancy corrections 

24. Further benefits can be derived by the increased fire performance specifications which include: 

1. Improved fire safety and the reduction in fire spread, damage and casualties in the event of a fire 

2. Standardised and improved features improve fire service operations and pre-planning allowing for a faster and safe emergency response 

3. Clarity for insurers and financiers reducing the perceived fire risk leading to improvements in underwriting and financing conditions 

25. Further generalised benefits include the wellbeing benefit of residents who feel safer in their homes.  

Transition Periods

26. Following public consultation, we will finalise the guidance and publish a full consultation response once all of the inputs have been adequately considered. All the proposals outlined within this consultation have a target implementation date of 2^nd September 2029. This implementation date aligns with the existing 2029 amendment booklet to Approved Document B and enables a full new version of ADB to come into effect from that date.  

27. By aligning the transition dates, we simplify when changes take place and make the guidance within ADB clearer. The alignment also provides an extended transition period allowing industry more time to adapt to the new guidance and minimise impacts on buildings currently within the planning process.  

28. Through the impact analysis supporting this consultation, a 2-year transition has been assumed. There is the potential for the actual transition period to be longer.