Do I need building regulation approval?

Most building work will require building regulations approval. This is a different requirement to planning permission, and must be applied for separately.

Ensuring that buildings are constructed to an agreed standard, the regulations are complex, but are essential to promote accessibility, health and safety and energy efficiency in the home.

Building work that requires approval

Many popular home improvement projects require approval, including conversions, extensions and cavity wall insulation.

The following types of project are regulated:

  • Structural alterations to the building
  • Most extensions to a building including conversion of a loft and garage conversions, but excluding porches and conservatories (see exemptions below)
  • Structural alterations, such as removing a load-bearing wall
  • When installing replacement windows using a builder or window company that is not registered with the relevant Competent Person Schemes
  • Installation of heating, hot water and air conditioning systems
  • Installing additional bathroom fittings
  • Domestic electrical installations
  • Alterations to drainage systems
  • Re-roofing (if it is greater than 25% of the roof)
  • Replacing windows, doors or roof lights
  • Underpinning a building
  • Renovating a thermal element e.g. walls, floors and roofs
  • Changing the energy status of a building
  • Changing the use of a building e.g. barn conversions


Building regulations do exempt some buildings from the need to make an application. These include:

  • Detached buildings housing machinery or plant which people do not visit except for maintenance or repair.
  • Certain greenhouses and agricultural buildings.
  • Small detached buildings under 30 sq. metres where no sleeping accommodation is provided.
  • Extensions of a building by the addition at ground level (i.e. on it's own foundations) of the following: - Conservatories, Canopies, Porches, Covered Ways and Car Ports, all with a floor area not exceeding 30 sq. metres.
  • Temporary buildings that are not intended to remain in place for more than 28 days.

Are you building sustainable drainage (SuDs)?

From 7 January 2019, all new developments of more than one house or where the construction area is of 100m2 or more will require sustainable drainage to manage on-site surface water. 

SAB approval is different and separate to planning permission and both must be sought before any construction can begin.

Visit our SAB pages to find out more

Please visit the planning portal ‘Do you need permission’ website for guides and examples of where building regulations may be required. 

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