Additional considerations

Particular attention is drawn to the following points.
a. Membranes used as part of the external wall construction above ground level should achieve a minimum of class B-s3, d0. Roofing membranes do not need to achieve a minimum of class A2-s1, d0 when used as part of a roof connecting to an external wall.
b. Internal linings should comply with the guidance provided in Section 4.
c. Any part of a roof should achieve the minimum performance as detailed in Section 12.
d. As per regulation 7(3), window frames and glass (including laminated glass) are exempted
from regulation 7(2). Window spandrel panels and infill panels must comply with regulation 7(2).
e. Thermal breaks are small elements used as part of the external wall construction to restrict
thermal bridging. There is no minimum performance for these materials. However, they
should not span two compartments and should be limited in size to the minimum required
to restrict the thermal bridging (the principal insulation layer is not to be regarded as a
thermal break).
f. Regulation 7(2) only applies to specified attachments. Shop front signs and similar attachments are
not covered by the requirements of regulation 7(2), although attention is drawn to paragraph 10.21g.
g. While regulation 7(2) applies to materials which become part of an external wall or specified
attachment, consideration should be given to other attachments to the wall which could
impact on the risk of fire spread over the wall.
h. Any material achieving class A1fl or A2fl-s1 in accordance with BS EN 13501-1 is exempted when it
meets both of the following conditions.
i. It forms the top horizontal floor layer of a balcony.
ii. It is provided with an imperforate substrate under it which extends to the full size of the
class A1fl or A2fl-s1 material.