Last edited 28 Aug 2017

Unprotected area

According to Approved Document B1 of the Building Regulations, 'Fire Safety: Dwellinghouses', the term 'unprotected area' in relation to a side or external wall of a building means:

a. Window, door or other opening; and

b. Any part of the external wall which has less than the relevant fire resistance set out in Section 8.

c. Any part of the external wall which has combustible material more than 1mm thick attached or applied to its external face, whether for cladding or any other purpose. (Combustible material in this context is any material which does not have a Class 0 rating.)

Note: Windows that are not openable and are designed and glazed to provide the necessary level of fire resistance need not be regarded as an unprotected area.

According to Approved Document B2 of the Building Regulations, 'Fire Safety: Buildings other than dwellinghouses', the term 'unprotected area' in relation to a side or external wall of a building means:

a. Window, door or other opening; and

b. Any part of the external wall which has less than the relevant fire resistance set out in Section 12; and

c. Any part of the external wall which has combustible material more than 1mm thick attached or applied to its external face, whether for cladding or any other purpose (Combustible material in this context is any material which does not have a Class 0 rating.)

Note: Windows that are not openable and are designed and glazed to provide the necessary level of fire resistance and recessed car parking areas shown in Diagram E1, need not be regarded as an unprotected area.

Diagram E1 recessed car parking areas.jpg

[edit] Find out more

[edit] Related article on Designing Buildings Wiki