Before starting any building work in England and Wales, you need to make sure you comply with Building Regulations. Set out by the Department for Communities and Local Government, Building Regulations are concerned with the health and safety of people in and around buildings. They apply to nearly all types of new builds and renovation work. Whoever physically carries out the work is responsible for compliance. So if you hire a contractor, it falls to them, or if you’re doing the work, it’s up to you. The owner of the building will be served an enforcement notice if the work doesn’t comply, so it’s definitely a good idea to check compliance before starting.
Some work doesn’t need Building Regulations compliance, but your local council will be able to help you understand which procedures and requirements apply to your project.