Planning permission decides whether you can build. Building Regulations decide how it must be built. Almost every extension, loft conversion and garage conversion needs Building Regulations approval, whether or not it needs planning permission.
What Building Regulations cover
The regulations set minimum standards for structure, fire safety, insulation and energy efficiency, ventilation, damp proofing and safe access. Building Control, at your council or a registered building control approver, checks the work as it is built.
The Building Notice route
For most home extensions and lofts you can use a Building Notice. You notify Building Control before work starts, and they inspect at key stages on site. Some work, such as building close to a public sewer, needs a full plans application instead.
What the technical pack gives your builder
A technical pack turns your approved design into drawings your builder can price and build from: technical floor plans, sections and elevations, roof, floor and wall build-up details, insulation and thermal specification, fire safety and means of escape notes, and construction specification notes.
Clear technical drawings help builders give comparable quotes, and give Building Control the information they need on site.
This guide is general information about the rules in England, not advice on your property. Always check with your council before you build.