Outbuildings can often be considered permitted development, not requiring an application for planning permission, provided they meet all the necessary criteria and there are no constraints that restrict or remove permitted development rights. If your intention is to convert a garage into a separate house (regardless of who will occupy it), then planning permission may be required no matter what work is involved.

Planning permission laws for outbuildings apply to sheds, playhouses, greenhouses and garages as well as other ancillary garden buildings such as swimming pools, ponds, sauna cabins, kennels, enclosures (including tennis courts) and many other kinds of structure for a purpose incidental to the enjoyment of the dwellinghouse.

Outbuildings are considered to be permitted development, not needing planning permission, subject to the following limits and conditions:

  • No outbuilding on land forward of a wall forming the principal elevation.
  • Outbuildings and garages to be single storey with maximum eaves height of 2.5 metres and maximum overall height of four metres with a dual pitched roof or three metres for any other roof.
  • Maximum height of 2.5 metres in the case of a building, enclosure or container within two metres of a boundary of the curtilage of the dwellinghouse.
  • No verandas, balconies or raised platforms (a platform must not exceed 0.3 metres in height).
  • No more than half the area of land around the “original house”* would be covered by additions or other buildings.
  • In National Parks, the Broads, Areas of Outstanding Natural Beauty and World Heritage Sites the maximum area to be covered by buildings, enclosures, containers and pools more than 20 metres from the house to be limited to 10 square metres.
  • On designated land* buildings, enclosures, containers and pools at the side of properties will require planning permission.
  • Within the curtilage of listed buildings any outbuilding will require planning permission.

The term “original house” means the house as it was first built or as it stood on 1 July 1948 (if it was built before that date). Although you may not have built an extension to the house, a previous owner may have done so.

It is important to note that permitted development allowances for outbuildings applies to houses but not to flats and maisonettes. All flats and maisonettes will require full planning permission.

If there are any constraints that limit or remove permitted development rights or even one of these criteria is not met, then you are required to submit an application for planning permission.

If planning permission is required but the works are completed without first securing the proper planning approval you may face retrospective planning issues. If the local planning authority determine that planning permission was required an enforcement and or penalties may be issued. If planning permission cannot be secured retrospectively the converted loft may need to be put back to its original state.

If you are in any doubt our expert planning consultants can help. By carrying out a planning appraisal we can advise you on whether planning permission is required, the feasibility, process, timescales, likelihood of success and answer any other questions that you have. Once we know exactly what is required for your project, we will provide you an accurate quote for us to help you.

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