The Building RegulationsThese are the legal regulations which govern how a house is constructed. (not to be confused with Planning Permission which is about whether you are allowed to build the house at all or what it might look like) see Building Regulations), part LThe Building Regulations, part L is the section which covers energy conservation for new buildings (with part L1A covering new buildings and part L1B covering existing ones), is the section which covers energy conservation for new buildings (with part L1A covering new buildings and part L1B covering existing ones)

At present there is a period of transition which is well explained in an NHBCThe National House-Building Council describes itself as being “the leading warranty and insurance provider [...]