29 April 2020
Take advantage of the extension to the fire-related Government consultation
The government has extended the consultation on Review of the ban on the use of combustible materials in and on the external walls of buildings until 25 May 2020 because of the impact of the Coronavirus. We would like to encourage, therefore, all our members who have not yet responded to do so using their own words.
Timber has proven itself capable, both structurally and in terms of fire safety, when used as the main structural material in mid-rise buildings. The Grenfell Tower fire identified a large number of failings – but the fire performance of the building’s structural material was not one of them. We are concerned to see, therefore, disproportionate measures being proposed, which would unnecessarily and negatively affect the ability to use timber in mid-rise construction.
If there is clear evidence from fire statistics and / or practically based fire research tests that there is a problem with the use of any given material or technique, then we are fully supportive of more robust requirements to address it. However, in order to give balance to the many issues we must address – and this definitely includes using sustainable building materials – we must ask that requirements are not tightened up where there is insufficient evidence or arguments for doing so. Our functionally based approach to building regulations has stood the test of time and should not be muddled with.
The key principles, which we outlined some weeks ago, which we have used when developing our response are as follows:
1. The mixing of our now long-established functional approach with a prescriptive approach.
We moved over to a functional approach to building regulations in 1985 and it has stood us in good stead. Mixing two different approaches is generally inadvisable, as engineers will know when they transitioned from the former British Standard approaches to the Eurocodes. All sorts of loopholes, unintended consequences and irregularities are created if you are not careful. This topic is discussed in some considerable detail by Angus Law, BRE Lecturer in Fire Safety Engineering, University of Edinburgh, and Neal Butterworth, Director of Design Fire Consultants, in an article published by ICE entitled Prescription in English fire regulation: treatment, cure or placebo?
2. Changes not informed by evidence.
TRADA understands that, for many years, significant changes to specific aspects of the building regulations have been informed by appropriate research – whether it be desk-based or physical experimentation – to confirm that any changes made are justified and proportional. The changes announced in this latest consultation are stated within the consultation itself to have not been researched, and that this is intended to be undertaken later.
The consultation asks for evidence by anyone suggesting tighter or looser recommendations than the ones proposed – but there is no evidence or methodology to justify what is being proposed. It is, therefore, not possible to properly conduct this debate now or in the future when we are considering other changes that become necessary. Like a good building, our regulations must be based on sure foundations in order to stand the test of time.
3. The approach taken has created a number of very significant unintended consequences.
One of these is that there are now many buildings that were compliant with Building Regulations at the time of being constructed a few years ago but which now appear to be judged by others to be ‘unsafe’. Whilst there is no requirement under Building Regulations to retrospectively upgrade these buildings, other factors such as mortgageabilty and insurability have had a very big impact on residents in medium-rise developments, for example.
4. The references and use of the Scottish approach is confusing and out of alignment with how the 11 metre trigger threshold for non-combustible materials is used in Scotland.
The Scottish approach, as defined in section 2.7 of the Scottish Building Standards Technical Handbook, uses an 11 metre threshold as a backstop position. It allows a higher threshold where either:
- provision acceptable to the fire service is made for fire appliances with greater reach; or
- test evidence for the overall cladding system to BS8414 (a functional approach previously permitted within the English regulations) proves the suitability of the system. In addition, the Scottish Standards only require non-combustible materials on the external and internal surfaces and not the structural members.
Overall, this seems a more proportional and functionally-based response than what is being proposed for England.
28 July 2020
New TRADA Topic – Sustainability
28 July 2020
External timber cladding – updated guidance
28 July 2020