Introduction

The Building Regulations, Approved Document B states that materials which become part of an external wall, or the external surface of a wall, shall be of the European Classifications set out in the document. For your convenience, we have outlined extracts from the following regulations:

• For detailed guidance, refer to the full versions of the regulations linked above.

Approved Document B: Fire safety (Volume 1: Dwellings)

2019 edition incorporating 2020 and 2022 amendments for England

Requirement B4: External fire spread

(1): The external walls of the building shall adequately resist the spread of fire over the walls and from one building to another having regard to the height, use and position of the building.

Regulation 7 – Materials and workmanship

7(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 A1 (classified in accordance with the reaction to fire classification).

7(4) (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.

7(4) (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.

Resisting fire spread over external walls

10.14: Regulation 7(2) applies to any building with a storey at least 18m above ground level and which contains one or more dwellings; an institution; or a room for residential purposes.  It requires that all materials which become part of an external wall or specified attachment achieve class A2-s1, d0 or class A1 in accordance with BS EN 13501-1, other than those exempted by regulation 7(3).

Note:

• Included are student accommodation, care homes, sheltered housing, hospitals, dormitories in boarding schools, hotels, hostels and boarding houses.

• An external wall includes anything located within any space forming part of the wall (including air bricks, plenums, HVAC supply and extract ducting, ventilation grilles, and cavity weep hole ducts).

• A specified attachment includes a balcony attached to an external wall, a device for reducing heat gain within a building by deflecting sunlight which is attached to an external wall and a solar panel attached to an external wall.

Combustibility of external walls

10.4: In relation to buildings of any height or use, consideration should be given to the choice of materials (including their extent and arrangement) used for the external wall, or attachments to the wall (e.g. balconies, etc.), to reduce the risk of fire spread over the wall.

External surfaces

10.5: The external surfaces (i.e. outermost external material) of external walls should comply with the provisions in Table 10.1.  The provisions in Table 10.1 apply to each wall individually in relation to its proximity to the relevant boundary.

The Building Safety Act 2022

Part 5: Remediation of certain defects

The reforms in this Act provide residents and homeowners living in multi-storey buildings with more rights, powers, and protections for safer homes, e.g., the remediation of the external walls of relevant buildings.

117 (2): “Relevant building” means a self-contained building, or self-contained part of a building, in England that contains at least two dwellings and
(a) is at least 11 metres high, or
(b) has at least 5 storeys.

Rytons A1^® Fire-rated Range