Government ban on combustible materials in external walls of high rise buildings

The Government yesterday (29 November) announced changes to the Building Regulations in order to implement the long expected ban on the use of combustible material in the external walls of certain high-rise buildings.

Building (Amendment) Regulations SI 2018/1230 will come into force on 21 December 2018.

The ban applies to the entire external wall construction, and not just the cladding.

The ban is being implemented by amending Regulation 7 of the Building Regulations, which deals with materials and workmanship. In addition to the current text (which becomes 7(1)), three new paragraphs have been added. The new text says:

‘(2) Subject to paragraph (3), building work shall be carried out so that materials which become part of an external wall, or specified attachment, of a relevant building are of European Classification A2-s1, d0 or Class A1, classified in accordance with BS EN 13501-1:2007+A1:2009 entitled “Fire classification of construction products and building elements. Classification using test data from reaction to fire tests” (ISBN 978 0 580 59861 6) published by the British Standards Institution on 30th March 2007 and amended in November 2009.’

The text above refers only to material reaction to fire classifications in accordance with the European classification system. The British Standard classification is not included in the new Regulation, and therefore terms such as ‘class 0’ and ‘limited combustibility’ will no longer be applicable to ‘relevant buildings’.

The second new paragraph (7(3)) lists components that are exempt from the ban, and states:

‘(3) Paragraph (2) does not apply to —

(a) cavity trays when used between two leaves of masonry;

(b) any part of a roof (other than any part of a roof which falls within paragraph (iv) of regulation 2(6)) if that part is connected to an external wall;

(c) door frames and doors;

(d) electrical installations;

(e) insulation and water proofing materials used below ground level;

(f) intumescent and fire stopping materials where the inclusion of the materials is necessary to meet the requirements of Part B of Schedule 1;

(g) membranes;

(h) seals, gaskets, fixings, sealants and backer rods;

(i) thermal break materials where the inclusion of the materials is necessary to meet the thermal bridging requirements of Part L of Schedule 1; or

(j) window frames and glass.’

New paragraph 7(4) sets out where these new restrictions apply:

‘(4) In this regulation —

(a) a “relevant building” means a building with a storey (not including roof-top plant areas or any storey consisting exclusively of plant rooms) at least 18 metres above ground level and which—

(i) contains one or more dwellings;

(ii) contains an institution; or

(iii) contains a room for residential purposes (excluding any room in a hostel, hotel or boarding house); and

(b) “above ground level” in relation to a storey means above ground level when measured from the lowest ground level adjoining the outside of a building to the top of the floor surface of the storey.’

By including institutions it also covers residential schools, care homes and hospitals, student residences or other institutional accommodation blocks.

The Government has also issued amendments to Approved Document B (ADB) to support this new regulation and a new paragraph in Approved Document 7 (AD7), which refers the reader to the revised ADB. Revised versions of ADB including wider clarifications are due in the spring, and it is expected that they will incorporate the changes in the Regulations. Therefore the amendments to ADB are themselves ‘transitional’.

Further amendments include changes to Regulation 2 relating to the definition of the external wall and ‘specified attachments’ (such as balconies and shading devices), and Regulations 5 and 6 relating to material change of use. It is worth noting the significance of this last change. A hotel may be built using materials not permitted in a student residence, but the hotel cannot later be converted to a student residence without any non-compliant materials being replaced. Therefore even if the materials used in a high-rise building are not initially covered by Regulation 7(a)(i) or (ii), consideration should be given to the potential future use of that building, and materials selected appropriately.

After the amended regulations come into force on 21 December 2018, there is a two month transition period. MHCLG have published a circular letter (linked below) which sets out the transitional arrangements. In addition to the advice given in the circular, it would also be prudent to discuss any transitional arrangements with insurers.

The following documents published yesterday by the Government provide further details of the changes;

1 Written Ministerial Statement.

2 The Building (Amendment) Regulations.

3 Amendments to Approved Document B2.

4 Amendments to Regulation 7.

5 MHCLG Circular letter and Circular 02/2018, which describes the amendments more fully. circular-022018

The summary above is our initial interpretation and understanding of the new changes. We also encourage you to read through the documents yourself. We will be studying these documents in further detail over the coming weeks and will look to publish further guidance in the near future.

If you have any questions or comments regarding the changes outlined above, or any concerns regarding their implementation and any effects this might have on façade construction and performance, please email CWCT ( with details.

Next post


Leave a comment