Government bans the use of combustible materials in buildings over 18m

The Government has published amendments to Building Regulations in England restricting the use of combustible materials in the external walls of certain buildings over 18m in height.

The restrictions apply to the external walls and specified attachments for residential blocks of flats, student accommodations, care homes, sheltered housing, hospitals and dormitories in boarding schools with a storey above 18 m in height.

Definitions of external walls and specified attachments

The amendments require that all materials which become part of an external wall or specified attachment achieve European Class A2-s1, d0 or Class A1.

The external wall of a building includes a reference to:

1)    anything located within any space forming part of the wall

2)    any decoration or other finish applied to any external (but not internal) surface forming part of the wall

3)    any windows and doors in the wall

4)    any part of a roof pitched at an angle of more than 70 degrees to the horizontal if that part of the roof adjoins a space within the building to which persons have access, but not access only for the purpose of carrying out repairs or maintenance.

Specified attachment means:

1)    a balcony attached to an external wall

2)    a device for reducing heat gain within a building by deflecting sunlight which is attached to an external wall

3)    a solar panel attached to an external wall.

Components exempted from this requirement include:

1)    cavity trays when used between two leaves of masonry

2)    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

3)    door frames and doors

4)    electrical installations

5)    insulation and water proofing materials used below ground level

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

7)    membranes

8)    seals, gaskets, fixings, sealants and backer rods

9)    thermal break materials where the inclusion of the materials is necessary to meet the thermal bridging requirements of Part L of Schedule 1

10) window frames and glass.

Transitional Provisions

The Amendment Regulations came into force on 21 December 2018. However the Amendment Regulations will not apply where an initial notice has been given to, or full plans deposited with, a local authority before 21 December 2018 and either the building work to which it relates:

a)    had started before that day; or

b)    was started before 21 February 2019.

Material change of use

Where the use of a building is changed such that the building becomes a residential block of flats, student accommodation, care home, sheltered housing, hospitals or dormitories in boarding schools with a storey above 18 m in height the construction of the external wall, and specified attachments, must be investigated and, where necessary, work must be carried out to ensure they only contain materials achieving European Class A2-s1, d0 or European Class A1 other than those exempted components listed above. 

Relevant statutory instruments, amendment regulations and Approved Documents

• Circular Letter 02/2018 and  Building (Amendment) Regulations 2018
• Amendments to Approved Document 7 – Materials and Workmanship
• Amendments to Approved Document B – Volume 2 – Fire Safety
• Regulatory Impact Assessment

For more information on the amendments and how these may affect your project please speak to your NHBC Surveyor or Project Manager