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.