Specification Online reported on the submission by RIBA to the government’s review consultation for the combustible materials ban on external walls of buildings, stating within it that the ban – first 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’.
It also called for the ban to apply to ‘key materials in external walls only’, and if this was not the case, the list of exempt materials ‘must be clarified and should include all materials that do not contribute to the spread of fire across external walls’. RIBA recommended that within external wall construction, the ban ‘should only restrict plasterboard, sheathing boards, insulation, outermost cladding materials’ and ‘significant materials’ used in other parts of external areas.
These include balconies, brise soleil and ‘similar building elements’ to the European classification A2-s1, d0 or A1, while the ban should also ‘not include the building’s primary structure’, as this should have ‘adequate fire protection’ as set out in requirement B3 of the building regulations – and ‘when included in the external wall’ it should still meet requirement B4.
RIBA explained that ‘further research into the use of structural timber within external walls’, such as cross laminated timber, ‘should be undertaken to determine performance when subject to real fire loads’. The ban should also be extended ‘on a precautionary basis’ to include relevant buildings that have a storey above 11m, ‘pending further research to determine the appropriate height threshold’, including fire and rescue service intelligence.
It concluded by stating its belief that the ban should ‘extend’ the restriction on combustible materials ‘to prevent further loss of life’. RIBA recommended that if the Ministry for Housing, Communities and Local Government did not ‘alter the ban to only include these materials’, then it should ‘provide clarity’ on those exempt, and include additional materials ‘that do not significantly increase the potential fire load of external walls’.
Jane Duncan, chair of RIBA’s expert advisory group for fire safety, commented: ‘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.’