Which projects need building control?

 You will usually need building regulation control if you 

  • put up a new building or extend an existing one
  • alter a building, like re-roofing, removing structural walls or chimney breasts
  • change a building’s use, like converting a garage into a lounge or a house into flats
  • install services or fittings in a building, like washing and toilet facilities or replacement windows

You might also need planning permission for your project, which is separate to building control . Find out by visiting the Planning Portal (Opens in new tab) website.

Things you will not need building control for

  • Detached single-storey buildings (with no sleeping area)
  • under 15 square metres, like greenhouses or garden sheds
  • a floor area no bigger than 30 square metres, like a detached garage. The building must also be at least one metre from the property’s boundary, or mostly made of non-combustible material

Extensions

  • a conservatory or porch at ground level with a floor area no bigger than 30 square metres, providing it is thermally separated from the house. The glass must meet the regulation standards, meaning you should use safety glass for most doors and adjacent windows and for windows with sills less than 0.8 metres above the floor
  • a carport (open on at least two sides) with a floor area no bigger than 30 square metres

Remember: electrical installation work may be covered by the building regulations even if the structure itself is not.

Last modified: 17/03/2026