When you build a new property, or carry out certain alterations to an existing property (e.g. building an extension, removing walls, or installation gas appliances) then the works may need to be signed off to confirm that the works comply with The Building Regulations 2010. You must check if you need building regulation approval before going ahead with carrying out any work to the property. Building regulation approval differs from planning permission.
More information on building regulations can be found here.