In this guide
Most extensions of properties require approval under the Building Regulations.
There are a number of classes of new buildings or extensions of existing buildings that do not need Building Regulations approval, i.e. are exempt from the Regulations.
The following common work sections give an indication of several other elements normally required to satisfy the requirements of the Regulations when building an extension:
You must also find out whether work you intend to carry out falls within The Party Wall etc. Act 1996.