Mitch Gee, Executive Chairman
Dame Judith Hackett’s interim review of Building Regulations and Fire Safety advised that the Government should significantly restrict the use of desktop studies to approve changes to cladding systems.
The Secretary of State made the following commitment:
‘’On desktop studies we will revise the approved documents on fire safety and commission work to produce a new British Standard on how such assessments can be used.’’
There are 4 routes to compliance:
- Linear route – all elements of the façade are of limited construction or better (non-combustible in Scotland)
- Fire safety engineering route – the whole building is assessed for spread of fire which is undertaken by a fire engineer
- Undertake full scale fire test BS8414
- Assessment in lieu of test – this route will be available if there is only a slight variation in design from the original BS8414 test.
The consultation paper seeks views on whether Government should prohibit the use of assessments in lieu of tests either for all fire tests classifications or for the fire test classifications relating to BS8414 full scale cladding test.
I think most in the EWI industry would support this approach as the EWI sector has traditionally undertaken full-scale fire tests for systems offered for use over 18m. It is obviously not practical to eliminate all assessments in lieu of tests, but as an industry we would support there use be significantly curtailed.
The current Building Regulations require that the external walls on all buildings adequately resist the spread of fire. This needs to be demonstrated in one of two ways:
- Each individual component of the wall meets the required standard for combustibility
- That all combined elements of a wall when tested as a whole adequately resist the spread of fire to meet a set standard.
Some assessments in lieu of tests of cladding systems have been criticised for their lack of supporting data. An assessment in lieu of test should be an extrapolation or interpolation of relevant existing test data, not an estimate. Questions have been raised over the competence of some assessment authors. The Government is proposing to issue amendments to Appendix A of Part B of the building regulations which will clarify the existing text and create new requirements for assessment in lieu of tests.
The Government has commissioned the British Standards Institution (BSI) to draft a standard for the extended application of BS8414 results.
Two scenarios are being considered:
- Make no changes to Approved document B to restrict the use of assessments in lieu of tests
- Issue amendments to Appendix A of approved document B and implement the changes which are being consulted on.
Alternatively, they could prohibit assessments for all fire tests or those specifically relating to BS8414.
The impact assessments predict a 25% increase in the cost of undertaking a more rigorous assessment in lieu of test in option 2, there being more assessments in lieu of tests as there will be greater confidence in them. The calculated impact of implementing proposed change to document B is £8.0m.
It should be noted that fire tests do not directly measure fire hazard. Performance in fire tests is only one of a number of factors that should be taken into account.
The policy objective is to tighten up the use of assessments in lieu of tests and ensure they are only used where appropriate with sufficient relevant test evidence, and they are undertaken by competent staff within appropriately certified organisations.
INCA’s position is that there should be least assessments in lieu of tests and more full-scale tests, which would reduce the potential for substituting products and increasing the risk of compromising the original system. There may be some requirement for minor changes such as fixing numbers or manufacturer, or different coloured finishes.
We welcome the input from our members before we respond to the consultation. We will be responding on Tuesday 22nd May.