Works requiring building control approvals
Building regulations approval is usually required if you intend to carry out work.
Please note: From Thursday 1 April, building control fees will be increased. Any building control applications received after 5pm on Wednesday 31 March will be subject to the new fees.
Works that require approval
- Changing the use of an existing building.
- Erecting or extending a building.
- Installing or extending a service or fitting, which is controlled under the regulations. This includes drains, some heating appliances and domestic, oil-fired heating or storage tanks.
- Inserting insulation into a cavity wall.
- Structural alterations, which will temporarily or permanently affect the ongoing compliance of the building, service or fitting with requirements relating to structure, fire or access to/use of buildings.
- Underpinning the foundations of a building.
- Work affecting the thermal elements, energy status or energy performance of a building.
Works that don't require permission
- Agricultural buildings and buildings used principally for keeping animals. These buildings must not be used as a dwelling, must be at least one-and-a-half times their height from any building with sleeping accommodation, and must have a fire exit not more than 30m from any point in the building.
- Carports open on at least two or more sides. Ends can be counted as sides and doors/windows are allowed between the house and carport.
- Conservatories built at ground level with less than 30m² in floor area, and built with safety glass and a transparent roof.
- Detached, single-storey buildings with a floor area not exceeding 30m², which do not contain sleeping accommodation, are located at least 1 metre from any boundary and are constructed of substantially non-combustible materials. For example, timber doors and gutter fascia boards are acceptable, as are flat roofs with mineral chippings on felt covering or pitched roofs with concrete or clay tiles.
- Greenhouses not used for retailing, packing or exhibiting.
- Porches built at ground level with a floor area less than 3m², which retain the existing house door.
- Temporary buildings erected for fewer than 28 days. This is provided glazing and any fixed electrical installations comply with the applicable requirements of the relevant building regulations (Part N and P).
Note: For most domestic extensions, if a building is exempt from building regulations approval, you may still need to comply with Part P of the building regulations, which covers electrical safety.
Still unsure whether your building work needs building regulations consent?
Find out more in the following ways:
- Use the Planning Portal Interactive House tool to help determine exactly what work requires building regulations approval.
- Refer to the Hillingdon guide to extending your home.
- For technical advice and guidance, contact Building Control Services by calling 01895 558170 or writing to:
Building Control Services,
You may also need to obtain planning permission for your project, which is entirely separate from the process of seeking building regulations approval. Planning permission relates to the proposed work and the effect it will have on neighbouring properties and the general environment.
Building regulations are concerned with the constructional details of building works to ensure the health and safety of people in and around the building.
Refer to the pre-application planning advice and guidance for more information on planning advice.