Cladding materials are classified by their reaction to fire under BS EN 13501-1. A1 and A2-s1,d0 are the two non-combustible or limited-combustibility classes most relevant to Building Regulations compliance.
A1 is the highest classification. Materials such as stone, brick and certain metal panels achieve A1 because they do not contribute to fire at all — no ignition, no heat release, no smoke.
A2-s1,d0 permits a very small combustible content (such as the core of some composite panels) but sets strict limits on smoke production (s1) and flaming droplets (d0). Many modern rainscreen and composite systems are manufactured to meet A2-s1,d0.
Following the Building (Amendment) Regulations, buildings over 11 metres in height (previously 18m) require external wall materials — including cladding, insulation and cavity barriers — to achieve at least European Class A2-s1,d0, with limited exceptions.
Below 11 metres, other fire-classified materials may be acceptable depending on the building's use and risk profile, but the requirement should always be confirmed against current Approved Document B and any relevant amendments before specification.
We confirm the applicable fire classification for your specific building — height, use class and location — before we specify any system, and provide full manufacturer test certification and classification reports as part of your project handover pack.
We confirm the right fire classification and cavity barrier detail for your building before we quote.