The open consultation on the Review of the ban on the use of combustible materials in and on the external walls of buildings has been extended until 25th May 2020.
ASBP submitted its response earlier in April and we encourage all of our members to respond online. We believe these are two of the key issues that should be addressed in a consultation response.
Risk assessment
Following a risk-based approach to avoid unintended consequences
Material toxicity
Assessing toxicity of materials both during and after exposure to fire
Risk assessment
Any reduction in the height ban and indeed, any height ban should be the result of a wide-reaching risk assessment conducted as part of the design process. Height is one factor to be considered amongst many in a risk-based approach to fire safety. Relying on one factor such as height above all others without a proper risk assessment may lead to an overweighting of that factor and the resultant unintended consequences thereafter.
Fire safety must be addressed at the design stage using a balanced and all-encompassing risk assessment that fully considers context. All independently verifiable evidence that allows for a balance risk-based assessment should be taken into account within a risk matrix for example allowing for context specific weighting.
Any further research carried out to inform the scope of the ban should include a detailed and comprehensive literature review that allows a balanced understanding of the available science and evidence.
For example, research could evaluate the importance of system testing, for example in accordance with BSEN13501-2/BS476 Part 20 in addition to BS8414 that is likely to give an additional real indication as to how a systems react in a real fire (either from inside the building or from outside of the building e.g. cladding).
The reason being that BS8414 is a test specifically for external cladding systems and is not giving a full indication of the performance of the rest of the system behind the cladding. This is important to note because the reaction to fire performance of the structural core of the external wall is assessed via EN13501-2/BS 476 Part 20/21/22.
We believe that including a definition of relevant buildings should not be done purely based on the building’s use. All evidence should be considered within the framework of a balance risk assessment that considers the building’s context in full. These factors should all be independently verifiable and considered within context with appropriate weighting during the design phase.
Material toxicity
The toxicity of materials with respect to fire should be an integral part of any risk assessment. This should include toxicity during the fire and toxicity of the materials after exposure to fire. The evolution of toxins from materials during fire is a principle cause of death and injury both to occupants and fire fighters. Moreover, significant exposure to the bi-products of fire can occur after the fire itself has been extinguished. Toxins are evolved from combustible and non-combustible materials alike. In fact, non-combustible materials exposed to fire or the chemical products of fire may be of a higher toxicity that the materials from which they arise.