The building regulations help ensure that new buildings, conversions, renovations and extensions are going to be safe, healthy and high-performing. Detailed regulations cover specific topics including: structural integrity, fire protection, accessibility, energy performance, acoustic performance, protection against falls, electrical and gas safety. The building regulations are defined by the English and Welsh Governments.

Construction work is signed off by a local authority inspector as the project progresses. You can also have your designs signed off for compliance before you start on site so that there are no nasty surprises.

The planning portal has lots of information about this too.