April 2024 Amends to Approved Document B

In the below article, we will cover the latest changes made to Approved Document B Fire Safety as of April 2024. Approved Document B Fire Safety offers guidance on fire safety covering various aspects such as means of escape, fire spread, structural fire protection, and fire service access, consisting of two volumes. Volume 1 addresses fire safety in dwellings, while Volume 2 pertains to fire safety in non-residential buildings.

In response to the Building Safety Act’s new requirements, updates are being made to the guidance provided in Approved Document B to enhance fire safety measures in buildings. On 29 March 2024, new guidance was added to page 29 section 3.30 of ADB, confirming the addition of two staircases in new residential buildings above 18 metres in height:

“Flats should be served by more than one common stair if either of the following applies.

a. The flat is on a storey that does not meet the criteria for a single escape route or a small single stair building (see paragraphs 3.27 and 3.32).

 b. The building has a top storey of 18m or more in height (see Diagram D6 in Appendix D).

3.31 Interlocked stairs should be considered as a single escape route and do not constitute an alternative means of escape.”

Transitional arrangements have been put in place indicating that until September 30, 2026, new Building Regulations applications can adhere to either the updated or the prior guidance. Following this date, applications following the previous guidance and where construction has commenced before that date will be given a grace period of 18 months to advance adequately.

Currently, Approved Document B does not specify a threshold for when more than one staircase should be considered necessary. Introducing a second staircase at a defined threshold would establish, for the first time in England, a maximum height for using a single staircase in residential buildings, offering clear guidance to designers to ensure residential buildings meet appropriate safety standards. Staircases serve as crucial escape routes during emergencies for residents and provide access points for emergency services to all floors of a building.

Implementing a solution that mandates a second staircase in buildings taller than 18m will ensure evacuation facilitation if a ‘Stay Put’ recommendation needs to be overridden. Additionally, the provision of a firefighting shaft, in addition to a protected staircase, is anticipated, alongside compliance with other provisions outlined in Approved Document B. The updated guidance will not mandate evacuation lifts by default, providing developers with clear directives for project advancement. Each high-rise building’s design will continue to undergo individual scrutiny by experts, now under the oversight of the Building Safety Regulator. Fire safety design for any higher-risk building over 18m will undergo review during Planning Gateway One by fire safety professionals and a multi-disciplinary team during Gateway Two.

Paragraph 3.49 in the previous instance will be replaced by the following guidance:

“Despite the provisions described, it is probable that some smoke will get into the common corridor or lobby from a fire in a flat. There should therefore be some means of ventilating the common corridors/ lobbies to control smoke and so protect the common stairs. This means of ventilation offers additional protection to that provided by the fire doors to the stair, as well as some protection to the corridors/lobbies.

Where evacuation lifts are provided, evacuation shafts should be afforded the same level of minimum protection as the stairway. Any smoke control system designed to protect the staircase should extend the same level of protection to the evacuation lift and evacuation lift lobby. Ventilation can be natural (paragraphs 3.50 to 3.53) or mechanical (paragraph 3.54).”

Future Changes

There are also further decisions that are pending regarding whether sprinklers will be mandated in all new care homes and whether construction products must adhere to testing based on the British standard version of the European standard, thereby eliminating the national classification system.

If you have a project and would like to understand more about the changes to ADB and how they affect your scheme, don’t hesitate to get in touch with one of our expert Fire Engineers.  


More Posts