Fire Safety for Relevant Buildings - Guidance Notes

External Wall Fire Safety for Relevant Buildings: Elements Resource Guidance Notes

The resource enables you to check the relevant regulatory and warranty (LABC Warranty) positions against a number of elements, systems, materials and arrangements of the external wall construction type.

It includes, where relevant, references contained within The Building (Amendment) Regulations 2018 and associated amendment to Approved Document B that came into force on 21 December 2018, in addition to existing requirements.

The amendment defines what constitutes an ‘external wall’ and restricts the use of combustible materials within these walls, when the walls form part of a ‘relevant building’ constructed in England. The amendment also details when certain materials will be exempt from the new requirements, and how the changes have implications for maintenance, upgrade or repair works to existing buildings.

Specific Guidance Notes

How the resource categories work

Elements: Key parts / assemblies of a façade. Comprised of a combination of systems, materials and components e.g. a balcony or a winter garden

Systems: Key external wall build ups or factory assembled unit e.g. rainscreen system or window screen

Materials and Components: Individual products which are combined to make up Systems and / or Elements e.g. infill spandrel panels and cavity trays.

Remediation / Change of Use: Relevant to existing buildings where works to the existing façade are proposed or the type of use / occupation of the building will be changed.

Definition of an External Wall

External wall:

a) includes a reference to

i. anything located within any space forming part of the wall;

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

iii. any windows and doors in the wall; and

iv. 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; and

(b) “specified attachment” means*

i. a balcony attached to an external wall;

iii. a solar panel attached to an external wall.”.

* MHCLG Circular letter, 10 December 2019 has removed B)ii) from the list of specified attachments.

Note: Pre-existing and un-amended requirements of the Regulations remain relevant to external walls, and must continue to be applied. Note in particular Schedule 1, Requirement B4-(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” noting that this requirement relates to all buildings of all heights.

Definition of a Relevant Building

Relevant Building:

(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—

  1. contains one or more dwellings;
  2. contains an institution; or
  3. 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.”

Warranty Position

LABC Warranty has engaged with appropriate organisations to compile this information. Please note, however, that positions shown here are those of LABC Warranty and cannot be attributed to other organisations.

When appropriate we have noted situations where other sectors of the industry may not be in full agreement with our position (noting that we believe our position to be substantiated and practical) and where it may be appropriate for you to seek specific guidance relevant to your project and circumstances.

Regulatory Position

This includes:

  • The Building (Amendment) Regulations 2018
  • Any associated amendment(s) to Approved Document B
  • Any FAQ and advice note documentation from the Ministry of Housing, Communities and Local Government (MHCLG), with links to documents where appropriate


This describes whether the item is exempt from Regulation 7(2), in accordance with Regulation 7(3), and any relevant references or statements in support of this. The resource also details any restrictions on the use of the item given in the guidance in Approved Document B Volume 2. Finally, the resource indicates whether B4 still applies and indicates the relevant reference.


Disclaimer: The information in this document is believed to be correct in light of information currently available and at the time of publication but is not guaranteed. Neither LABC Warranty nor its agents can accept responsibility in respect of the contents or any events arising from the use of the information contained within this site. The guidance provided does not replace the reader’s professional judgement and any construction project should comply with the relevant Building Regulations or applicable technical standards. For the most up to date LABC Warranty technical guidance please refer to your Risk Management Surveyor and the latest version of the LABC Warranty Technical Manual.