Part B · England · Free to use
Fire resistance periods
Minimum period of fire resistance for the structure by purpose group, sprinklers and height of the top storey.
Approved Document B Volume 2 (2026 PDF; table values effective until September 2029)
Your inputs
Results update as you type.
m
Part B · Result
60 minutes fire resistance
Sprinklered flats, top storey 16.8 m above ground.
Calculated result- Elements of structure, above ground: Calculated resultup to 18 m60 minutes
- Flats with a top storey over 11 m need sprinklers anyway (Vol 1 para 7.4).
- Compartment walls separating buildings: at least 60 minutes. Elements protecting means of escape: at least 30 minutes.
- Purpose groups 3 to 7(a) with a top storey over 30 m need sprinklers.
Clauses this relies on
Source edition and scope
Approved Document B Volume 2 (2026 PDF; table values effective until September 2029).
This is a preliminary check of the conditions shown. Confirm the edition, project circumstances and any additional requirements with your architect or building control.
A design aid, not legal advice. Checked against the Building Regulations 2010 for England; confirm with building control.