England Approved Document B
Circular letter on Approved Document B volume 1 and 2
Library captured 10 September 2026 · Source updated 26 May 2020
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To:
The Chief Executive:
Unitary, Metropolitan, District and London Borough Councils in England
County and County Borough Councils in Wales
The Town Clerk, City of London
The Clerk, Council of the Isles of Scilly
The Sub-Treasurer, Inner Temple
The Under Treasurer, Middle Temple
The Head of Building Control:
Unitary, Metropolitan, District and London Borough Councils in England
County and County Borough Councils in Wales
City of London
Council of the Isles of Scilly
Approved Inspectors cc: The Chief Executive:
County Councils in England
National Park Authorities in England & Wales
Chair: National Fire Chiefs Council
26May 2020
Dear Sir or Madam
Amendments to Approved Document B 2019
I am writing to inform you of the publication of amendments to Approved Document B (Fire safety) 2019 edition:
•Volume 1: Dwellings
•Volume 2: Buildings other than dwellings
Transitional arrangement
The changes in the amendment booklet take effect on 26 November 2020. The amendments do not apply in any case where a building notice or an initial notice has been given to, or full plans deposited with, a local authority and either the building work to which it relates has:
(a)started before that day; or
(b)is started before 29 January 2021.
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Scope of this Circular Letter
The guidance in this Circular Letter applies to buildings and building work in England.
Associated Publications from MHCLG
The amendment booklet which includes all changes to the guidance in Approved Document B (Fire Safety) 2019 edition, volumes 1 and 2 is available at:
https://www.gov.uk/government/publications/fire-safety-approved-document-b
The Government response to the consultation on sprinklers and other fire safety measures is available at:
The full impact assessment is available at:
Hard copies of Approved Document B (Fire safety) volume 1: Dwellings, 2019 edition (including amendments up to May 2020) and Approved Document B (Fire Safety) volume 2: Buildings other than dwellings, 2019 edition (including amendments up to May 2020) will be available from the publisher later in the year when the changes take effect. Versions from before that date will need to be read alongside the amendment booklet.
Summary of main changes
The changes focus on residential blocks of flats and mixed-use buildings containing flats.
Scope
These amendments to sprinkler provisions, and new guidance on consistent wayfinding signage, will apply to building works in a block of flats or mixed-use buildings containing flats with a top floor more than 11 metres above ground level. This includes the erection of new buildings, material alterations, material changes of use and extensions as set out in Regulation 3 of the Building Regulations 2010 (as amended).
Sprinklers
The amendments include a reduction in the height threshold for sprinklers in Purpose group 1a (residential (block of flats)) from 30 metres to 11 metres. As a result of the change to the height threshold, Table B4 (Minimum periods of fire resistance) will also be amended when these changes take effect to reflect that a block of flats without a sprinkler system above 11 metres is not permitted if following the guidance in the Approved Document.
There are no changes to Appendix E which will continue to recommend that sprinkler systems in residential blocks of flats are installed in accordance with the recommendations of BS 9251, or BS EN 12845 for residential blocks of flats outside of the scope of BS 9251. The Approved Documents will continue to note that sprinklers in residential blocks of flats do not need to be provided in common areas when these are fire sterile.
Wayfinding signage for the fire service
The amendments set out guidance for the provision of consistent wayfinding signage for use by the fire service in Purpose group 1a (residential (block of flats)) with a top storey more than 11 metres above ground level. Signage should include floor identification and flat indicator signs which provide information relating to the flats that are accessed on each
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floor. The amendments set out the recommended locations for this signage and guidance on typeface and wording. The amendments do not prescribe a particular material or technology that should be used for this signage, such as photoluminescent lettering. But they do set out that the signage should be on a contrasting background, easily legible and readable in low level lighting conditions or when illuminated with a torch. Designers should satisfy themselves and the relevant Building Control Body that their choice of design will meet these conditions.
Extensions
Applicants and building control bodies are reminded of the need to consider these new provisions in relation to extensions as required by Regulation 4(1). New accommodation, formed by building work, should meet the relevant requirements having considered the guidance in the approved document. This means ensuring that the standard of fire protection for the occupants of the new accommodation is as would be provided for a new building under the approved document.
In the majority of cases, therefore, sprinkler protection and wayfinding signage will be necessary in any newly formed accommodation that falls above the new 11m trigger height. It may also be necessary to consider additional protection for the existing parts of the building where needed to ensure that the extension is compliant with the applicable requirements of Schedule 1. Equally, it will be necessary to satisfy regulation 4(3) by ensuring that the level of fire protection in the building as a whole is made no worse.
There may also be situations where the risk assessment for the building (provided under the Fire Safety Order) requires further work to be done. Regardless of the minimum requirements of the regulations there is, of course, merit in providing additional protection throughout the building.
Boundaries
These amendments include fixing of a typographical error where Purpose group 2 was not referenced in the guidance on boundaries for residential buildings.
Enquiries
Telephone enquiries on this Circular Letter should be addressed to Technical Policy Division on 0303 444 0000 and all e-mail enquiries to enquiries.br@communities.gov.uk.
Yours faithfully
F Kirwan
Deputy Director
Technical Policy Division
Building Safety Portfolio