Amendments to Approved Document B (Fire Safety) published

Picture of fire sprinkler - including in Amendment to Approved Document B

The Government has published Amendments to Approved Document B of the Building Regulations (Fire Safety). Although only applicable in England, Wales already have a requirement for sprinklers in all dwellings including flats.

Changes will apply to blocks of flats or mixed use buildings containing flats with a top floor more than 11 metres above ground level. It includes new build, material alteration, material change of use and extensions.

The documents as amended take effect on 26 November 2020 except in respect of:

- Work subject to an initial notice (IN), building notice (BN) or deposit of full plans (FP) commenced before that date;

- OR, work for which a IN, BN or FP was given before 26 November 2020 and the work commences before 29 January 2021.

The main points

  • The height threshold for the provision of sprinklers is reduced from 30m down to 11m.
  • BS9251 or BS EN 12845 continue to be recommended for sprinkler system installations in flats.
  • There will be no recommendation for sprinklers to be provided in common areas when these are fire sterile (lacking in combustible materials.)
  • New guidance is included for the provision of consistent wayfinding signage for use by the fire service in flats with a top floor more than 11m above ground level.
  • Signage should include floor level identification and information about flats accessed on that floor.
  • The new provisions will apply to extensions so that sprinkler protection and wayfinding signage will be necessary in any newly formed accommodation in buildings with a floor 11m or more above ground level.
  • An amendment to correct an omission in the redrafted document includes consideration of a notional boundary between buildings of purpose group 2 where both buildings are managed by the same organisation.

Further information

View England Approved Document B and May 2020 Amendments

View Wales Approved Document B 


Please Note: Every care was taken to ensure the information was correct at the time of publication. Any written guidance provided does not replace the user’s professional judgement. It is the responsibility of the dutyholder or person carrying out the work to ensure compliance with relevant building regulations or applicable technical standards.


Cladding no alteration on the height

Submitted 1 year 9 months ago

There appears to be no alteration on when fire resistance cladding height when comes in. So tower blocks will effectively be an up side down match. Has demonstrated in the fire in Manchester a few months ago.

Sprinklers in flats

Submitted 1 year 9 months ago

Dear team.
I would be grateful if you could clarify the note within your upgrade to ADB with regard sprinkler systems.
The guidance of the British standard, as well as guidance in the amendment would suggest the building as a whole should be considered with regard building being extended above 11m (floor level)
However you are stating that the amendments apply to the new extensions and that sprinklers and wayfinding will apply to newly formed accommodation. Assuming from this that the rest of the building does not.
I would be really grateful for your input as the whole thing appears open to interpretation at present.

Kind regards Darren


Submitted 1 year 9 months ago

Hello there - thanks for leaving your comment.

As indicated in your query and with all things associated with Approved Documents, things can be open to interpretation. This has been recognised by MHCLG and in an attempt to assist have issued a circular letter on the subject. This is available at

It is clearly expected that the existing part of the building should not compromise the safety of any new work and the circular gives guidance on the issues that should be considered.

Kind regards
Barry, LABC

Fire Boards

Submitted 1 year 4 months ago

I understand that Mg) Fire Boards are nom longer acceptable. Please advise what Fire Boards are acceptable.

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