London Borough of Barnet

When do building regulations apply?

Any person carrying out building work that falls under the categories set out below has a responsibility to comply with the Building Regulations.  This can apply to the client, owner, constructor, designer, supplier, etc.

Building Regulations apply when any of the following are carried out:

  • erect or re-erect a building or part of a building
  • extend a building
  • carry out external or internal alterations to a building that affect structural, fire safety, thermal performance and disabled provisions
  • convert a roof space
  • re-cover roofs or reclad a building
  • carry out underpinning
  • change the use of a building or part of a building
  • replace windows and doors
  • insert cavity insulation
  • install unvented hot water systems

Building Regulations cover the provision, extension or alterations of:

  • washing and sanitary facilities and fittings  
  • sanitary pipework  
  • foul and rainwater drainage  
  • sewage treatment plants and cesspools  
  • boilers, flues, chimneys and hearths  
  • fuel storage installations  
  • hot water storage and controls  
  • electrical installations to dwellings  
  • thermal elements      

Exempt works
Some types of building work may be carried out without submitting a Building Regulations application. The main types of works that are exempt are:

  • porches – if not used for any other purpose, e.g. does not contain a sink or w/c, is built on the ground, less than 30m², is separated from the dwelling by a suitable door and Regulations
  • conservatories – built on the ground, less than 30m², attached to the dwelling but separated by a suitable door. NB An application would be required for any new or enlarged structural opening
  • garages or small detached buildings less then 15m² with no sleeping accommodation
  • gor single storey detached buildings less than 30m² with no sleeping accommodation and either more than 1m from the boundary or constructed of non-combustible materials
  • greenhouses and agricultural buildings
  • carports –open on at least two sides
  • covered ways
  • detached buildings not normally used by people
  • temporary buildings – if they are to remain no longer than 28 days
  • construction site and sales office.

Please note that any glazing or fixed electrical installations would need to comply with the applicable parts of the Building Regulations. For a complete list of exemptions please refer to Schedule 2, 3 and 4 of the Building Regulations or check the Planning Portal website.

These exemptions cover:

  • detached garages having less than 30 square metres in floor area, and constructed of non-combustible materials
  • detached summer house having less than 30 square metres in floor area, and containing no sleeping accommodation and constructed of non-combustible materials
  • timber sheds are also exempt providing they are less than  15 square metres, or if between 15 and 30 square metres are positioned a minimum of one metre from the boundary.

Building Control

North London Business Park (NLBP), Oakleigh Road South, London N11 1NP

Tel: 020 8359 4500