It is generally realised that a form of permission is required for building work or alterations of properties. However, it may not always be clear how the planning and building regulations approval regimes differ.
Building regulations is set standards for the design and construction of buildings to ensure the health & safety for people in or about those buildings. They also include requirements to ensure that fuel and power is conserved and facilities are provided for people, including those with disabilities, to access and move around inside buildings.
Planning permission seeks to guide the way our towns, cities and countryside develop. This includes the use of land & buildings, the appearance of buildings, landscaping considerations, highway access and the impact that the development will have on the general environment.
For many types of building work, separate permission under both regimes (separate processes) will be required. For other building work, such as internal alterations, buildings regulations approval will probably be needed, but planning permission may not be.