Fire Resistance Calculator
Determine the minimum fire resistance period for structural elements per Approved Document B. Lookup Table A2 requirements by building height, purpose and element type.
Height of topmost floor above ground
Elements requiring protection
Fire protection cost per element
How We Calculate This
This calculator looks up the minimum fire resistance period from Approved Document B, Table A2 based on building parameters.
The lookup
Fire resistance = f(building purpose, height, element type, basement)
- Up to 5m: 30 mins (non-residential)
- 5-18m: 60 mins
- 18-30m: 90 mins
- Over 30m: 120 mins
- Residential (flats): 60 mins minimum at all heights per AD B Vol 1
- Basements: 60 mins (≤10m), 90 mins (>10m)
Frequently Asked Questions
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Last updated: March 2026
All calculations are estimates. Verify with your supplier.