Building regulations explained

When a building regulation application is required

You will need to apply for building regulation approval if work includes:

  • The erection or extension of a building
  • The installation of a new wc or bathroom that involves new waste pipes or underground drainage
  • The installation of a gas or solid fuel appliance (unless the work is supervised by an approved installer)
  • The conversion of a house to flats or vice-versa
  • General internal structural alterations e.g. the removal of loadbearing walls
  • Internal alterations affecting means of escape in case of fire
  • Conversion of loft space in dwellings (approval may also be required for loft storage)
  • Replacement glazing in doors and / or windows in dwellings (unless supervised by competent body)
  • Fitting replacement roof coverings that are heavier / lighter in weight than the existing covering or where more than 25% of the roof covering is being replaced
  • Changing the use of certain buildings
  • Installation / testing of electrical installations in dwellings (unless supervised by Competent Body)
  • Underpinning of foundations
  • Renovation works where more that 25% of any thermal element is being effecte
  • Micro renewables

Approval to build a porch or conservatory

Most porches and conservatories are exempt from Building Regulation approval if they meet the following basic criteria:

  • Separated from the dwelling by walls, doors and / or windows
  • Built at ground level
  • Under 30m² in floor area
  • Glazing complies with the safety glazing requirements of the Building Regulations
  • The existing heating system is not extended into the conservatory

Please note:

  • A conservatory requires a glazed or translucent roof to satisfy this exemption.
  • You may need Building regulation approval for any electrical installations within these exempt structures if Part P (electrical installations in domestic buildings) is applicable.

It is advisable to ensure that a conservatory is not constructed, so that it restricts ladder access to windows serving a room in the roof space or a loft conversion, particularly if that window is needed as an emergency means of escape in the case of fire.


Approval to build a detached garage

Most standard size detached garages are exempt from Building Regulation approval providing they meet the following criteria: 

  • a single storey garage built at ground level
  • under 30m² in floor area and with no sleeping accommodation
  • and either:
    • it is built substantially of non-combustible material;
    • or when built it has a clear space of 1 metre from the boundary of the property.