Calls to extend restriction on combustible materials
03 June 2020
THE ROYAL Institute of British Architects (RIBA) has responded to the UK Government’s review of the restriction on combustible materials in and on the external walls of buildings.
The RIBA recommends that the restriction introduced in December 2018 should:
- be extended to include hotels, hostels and boarding houses, and all buildings where a catastrophic event could cause multiple fatalities.
- apply to key materials in external walls only. If not, the list of materials exempt from the ban must be clarified and should include all materials that do not contribute to the spread of fire across external walls.*
- not include the primary structure of the building. Further research into the use of structural timber within external walls (e.g. cross laminated timber) should be undertaken to determine performance when subject to real fire loads.
- be extended on a precautionary basis to include relevant buildings with a story over 11m above ground level, pending further research to determine the appropriate height threshold. Research should include intelligence from fire and rescue services.
RIBA Expert advisory group for fire safety chair Jane Duncan said: “Almost three years on from the Grenfell Tower tragedy, hotels, hostels, boarding houses and other buildings with multiple and even vulnerable occupants are still being built using combustible materials on their external walls. Fires do not discriminate between building types or users, yet our regulations do. The restriction on combustible materials must be extended as a matter of urgency to keep people safe.
The restriction in its current form has caused confusion in the industry. The government must provide clear guidance, and fund research, to enable the construction of safe buildings whilst ensuring innovation can still take place to combat the climate crisis.”
Read the RIBA’s full consultation response here.
* The RIBA recommend that within external wall construction, the ban should only restrict plasterboard, sheathing boards, insulation, outermost cladding materials and significant materials in balconies, brise soleil, and similar building elements to European classification A2-s1, d0 or A1. The ban should not include the buildings primary structure. The primary structure should have adequate fire protection as set out in Building Regulations requirement B3 and when included in the external wall should still meet requirement B4. The RIBA recommend that if the MHCLG will not alter the ban to only include these materials, then the MHCLG should provide clarity on the list of materials that are exempt from the ban and should include additional materials that do not significantly increase the potential fire load of external walls. The full RIBA response includes recommendations for additional materials and systems that should be included in the exemptions list.