Government ban of materials rated less fire resistant than A2-s1, d0 in external wall build-ups - what exactly is the Government proposing?

Following its consultation proposing a ban on the use of materials that do not meet class A1 or A2 from use in external walls that are 18 meters or over, on 29 November 2018 the Government issued its response. The majority of respondents to the consultation (69%) submitted that combustible materials in cladding systems should be banned. Our review considers the key points of the response.

The ban of combustible materials will apply:

  • to all new residential buildings above 18 metres in height

  • to new dormitories in boarding schools, student accommodation, registered care homes and hospitals above 18 metres, and

  • where ‘building work’ is being carried out (in line with the definition of building work in the Building Regulations) including changes of use and material alterations. More on this below.

The Government has clarified that the height of a building will be measured from:

  • the lowest ground level adjoining the outside of an external wall, to

  • the finished floor surface of the top occupied storey.

The threshold of 18 metres will be reviewed, however, as part of the Government’s wider technical review of the building regulations for fire safety starting next Autumn. Respondents to the consultation highlighted the risk of buildings being deliberately designed just below the threshold, ie 17.96 metres. Suggestions were also made to follow the Scottish consultation threshold of 11 metres, or alternatively to adopt a purely risk-based system.

The ban will limit materials to products achieving a European Classification of Class A1 or A2-s1, d0, when tested in accordance with BS EN 13501-1:2007+A1:2009. This is in line with many other EU member states.


The Government has confirmed that exemptions will apply to components where non-combustible alternatives (i.e. products for) does not exist are not currently available. For example, products for which Class A1 or Class A2-s1, d0 does not exist or are not ‘readily available’.

The interpretation of ‘readily available’ is not explained in the Government response, and further guidance may be provided in the Approved Document B at a later stage.


The ban on combustible materials will be implemented through changes to the Building Regulations. The Government considers that transitional provisions will be necessary, however, it acknowledges that there is evidence of many projects already applying restrictions on the use of combustible materials.

The ban will apply to buildings where building work is being undertaken unless:

  • the building works have started on site

  • an initial notice, building notice or full plans have been deposited, or

  • work has started on site within a period of eight weeks.

The Government’s response does not set out a rationale for the above exceptions, which is surprising in light of the views of respondents to the consultation on this point. For example, in reply to the question: “do you agree that… the ban should extend to projects that have been notified before the ban takes effect but work has not begun on site”, 66% of respondents answered ‘yes’. The specific wording of a subsequent question about whether the ban should affect projects where building work has already begun was ambiguous, and the Government response noted that the answers collated may not be an accurate representation of the respondents’ views.

In addition, concerns were raised by respondents that developers may rush to submit plans before the ban comes into place, and that there would be financial implications for re-specifying plans and / or changing materials pre or during construction. This is interesting in the post-Grenfell era, and in light of the conclusions in Dame Judith Hackitt’s Final Report that a culture change was required to prioritise safety; it appears that the view from within the industry is that there is still some way to go in this respect.


Significant attachments such as balconies, photovoltaic panels, green walls and brise soleil will be included in the ban.

This document (and any information accessed through links in this document) is provided for information purposes only and does not constitute legal advice. Professional legal advice should be obtained before taking or refraining from any action as a result of the contents of this document.