New Approved Document B changes

In March 2025, several changes came into effect under Fire Safety: Approved Document B. On 30 September 2026, more changes will be coming, followed by further amends on 2 September 2029. 

The updates have been made to reflect the changing standards of the construction industry, prioritising fire safety at all times and ensure competent people are in place to carry out these changes from design to build to occupation. 

This blog explains: 

• What Approved Document B is 
• Who it affects and should be aware of the document 
• Its development so far through the amendments and updates 
• When the next updates take place 
• How to view your supply chain’s compliance with the Building Safety Act and minimise risk 
• Where to find guidance on understanding the Building Safety Act 

 

What is Approved Document B? 

Fire Safety: Approved Document B is a Building Regulation in England that covers fire safety matters within and around buildings.  

It provides guidance on how to meet the building regulations for fire safety in England and Wales, focusing on imperatives such as how to: 

	Limit the spread of fire within and between buildings
	Ensure escape routes are protected and accessible
	Provide access and facilities for firefighters
	Give fire safety information to building users

 

Who does Approved Document B affect? 

All dutyholders are affected. They need to make sure everything is maintained in accordance with Approved Document B: 

Principal Designers 

Have to ensure their designs are compliant with the Building Safety Regulations which includes: 

• fire safety; making sure their designs allow for routes of escape, compartmentation (reducing/stopping fire spread) 
• firefighting access; e.g. within this amendment, they need to make sure a second staircase is within their designs for new buildings, evacuation lifts are sorted etc. 

Principal Contractors 

They need to make sure the building is constructed in line with those designs… including all the new stuff from the approved doc…  

Designers and Contractors  

For Designers and Contractors working beneath Principal Designers and Principal Contractors, they will need to do the same and make sure that when they’re designing their parts, or constructing their parts of the work, they are compliant with the new measures. 

 

What changes were introduced in 2025? 

In March 2025, Approved Document B was amended to strengthen building fire safety and improve accountability, especially for main contractors. 

Ultimately, the changes aim to hold all key parties responsible for taking charge of fire safety in our buildings, creating an indisputable chain of evidence that fire safety matters have been addressed. 

What should fire safety information include? 

Approved Document B asks that an ‘as-built plan of the building’ is provided, showing all of the following: 

Principal contractors should also offer details on these three key areas:

1)	Fire safety equipment specifications – This should include routine maintenance schedules.
2)	Building management assumptions – These should be based on the design of the fire safety arrangements.
3)	Evacuation provisions – Specifically for those with disabilities, to help design personal emergency evacuation plans.

A detailed record of the building’s fire safety strategy should also be undertaken, and encompass procedures for operating and maintaining any fire protection measures.

Give all this fire safety information to the relevant dutyholder, and you can feel confident you’ve done your due diligence when it comes to fire safety concerns. 

 

What are the new key changes to Approved Document B in 2026? 

A few amendments have been introduced, including:  

• A second staircase for buildings over the 18-metre threshold 
• Supporting the use of evacuation lifts 
• Updates to escape and smoke control guidance 
• Clarifies related technical definitions and fire doorset requirements 

If contractors are already working on a higher-risk building (HRB) before 30 September 2026, the previous Document B applies. However, if starting work after this date (i.e. from 1st October 2026), contractors will need to follow these new updates. 

Stairs 

Blocks of flats with a top storey 18m or more in height should be served by more than one common stair. Single common stair arrangements are only suitable where the top storey is below 18m, subject to the relevant escape criteria. 

Evacuation lifts 

Introduction of design provisions to support the use of evacuation lifts in blocks of flats. Where provided, these should be located within an evacuation shaft containing: 

• A protected stairway 
• An evacuation lift 
• An evacuation lift lobby/refuge area 

Escape route and travel distance updates 

The amendments revise guidance on horizontal and vertical means of escape, including updated travel distance limits: 

• 7.5m where escape is in one direction 

• 30m where escape is in more than one direction 

Smoke control and protection 

Evacuation shafts and evacuation lift lobbies should receive the same level of protection as stairways, including smoke control where relevant. 

Fire doorsets 

Update to reflect fire resistance requirements for doorsets, including doors serving protected stairways, evacuation shafts, lobbies and corridors. 

New and updated definitions 

New definitions have been added for: 

• Evacuation lift lobby 
• Evacuation shaft 
• Interlocked stair 
• Storey exit 

 

When do the next changes come into effect? 

• 30 September 2026 – higher-risk buildings over 18 metres need evacuation lifts and 2 staircases 

• 2 September 2029 – the final amendment to Approved Document B will come into effect. This focuses on removing BS 476, which determines the appropriate fire tests for elements of structure and materials, from Approved Document B. Instead, it will be replaced by the European Standard (BS EN), which is deemed more current and robust than the present National Classes. BS EN will then be the sole route for specification within Approved Document B for fire resistance classifications. 

Do you know how many of your suppliers are aligned with the Building Safety Act? 

Get a one-click view of how many suppliers in your supply chain are aligned with the Building Safety Act, with our BSA Radar. 

Included in our buyer packages, BSA Radar helps main contractors: 

• View supply chain compliance with the Building Safety Act 
• Accelerate decision-making: see which suppliers have passed our Building Safety Act Assessments 

 

Next steps 

• If you’re a main contractor, make sure you’re aware of the updates to Approved Document B 

• Check out BSA Radar and get a better view of your Building Safety Act compliance amongst your suppliers 

• Use our BSA Hub to get in the know of all things Building Safety Act, whether you’re a beginner or experienced 

 

Key takeaways 

• The next key changes to Approved Document B come into effect on 30 September 2026 

• A second staircase must be included for buildings over the 18-metre threshold, as well as evacuation lifts 

• BSA Radar helps main contractors get a one-click view of their compliance with the Building Safety Act 

 

FAQs 

Why was Approved Doc B introduced? 

Fire Safety: Approved Document B deals with fire safety in and around buildings (in England and Wales) and falls under the Building Regulations 2010. It was introduced to define what counts as building work; the minimum standards for design and construction; identifies exemptions; and explains the procedures for starting, carrying out and completing building work. 

 

You can read the full published guidance here. 

 

This blog was updated in June 2026.