Permitted development for larger house extensions

Permitted development rights allow for some larger house extensions to take place without the need for planning permission, although there are restrictions on this.

If you want to carry out a development using these rights you will still need to tell us what you intend to do, and let us know when the work is complete.

Restrictions on rear extensions

  • the extension must be a single storey extension;
  • if the house is detached, the extension must not project more than 8 metres beyond the rear wall of the original house;
  • if the house is a terraced, semi-detached or linked-detached, the extension must not project more than 6 metres beyond the rear wall of the original house;
  • the extension must not exceed 4 metres in height;
  • the extension must not be within an Area of Outstanding Natural Beauty;
  • the extension must not be within a Conservation Area;
  • the extension must not be within a Site of Special Scientific Interest;
  • the total area of ground covered by buildings on the site (not including the original house) must not exceed 50% of the site;
  • if the extension is within 2 metres of the property boundary, the eaves of the extension must not exceed 3 metres in height;
  • the extension must not include or provide a veranda, balcony or raised platform, a microwave antenna, a chimney, flue or soil and vent pipe, or an alteration to the main roof of the house;
  • If the work started on or before 15/04/2015 the extension must be completed by 30/05/2016. If the development started after 15/04/2015 it must be completed by 30/05/2019; and 
  • before extending your home with a larger extension of this type you must apply to us to determine whether prior approval will be required.

Restrictions on front or side extensions 

Extensions to the side or front of the house are subject to other restrictions under existing permitted development rights. If you are considering a front or side extension to your home without making a full planning application you should check whether it would comply with these other restrictions.

Further guidance on existing permitted development rights is available through the Planning Portal or in the following document;

Permitted Development - Larger home extension guidance notes

Letting us know

Before extending your home with a larger extension of this type, or changing a commercial property, you must:

  • apply to us to see if our prior approval is required
  • provide us with a plan showing the location of your property and the position of the proposed extension. We may need additional drawings or elevations to make this determination.

There is no fee for this type of application.

Please complete a prior approval notification form and send it to us

Permitted Development - Prior approval form