Useful Information

Permitted Development Simplified.

Every year homeowners look to add living space and improve the re-sale value of their homes by improving and extending them.

Permitted Development Rights allow you to extend up to a given percentage in volume of an existing house and carry out certain improvements and extension works without seeking planning permission.

The criteria for work carried out under Permitted Development is very strict so it is advisable to check with your local authority planning office to confirm that planning permission is not required.

Below are the types of work can you carry out under Permitted Development.


  • Extend your property by up to 4m to the rear on a detached property or 3m on semi-detached / terraced property. (Height and rear boundary restrictions apply.)
  • The extension must not cover more than half of the garden.
  • You must not build forward of the original building line.
  • It must be built in the same or similar material to the existing property.
  • Side extensions are permitted, subject to height and width restrictions.


  • The external footprint must occupy no more than 3m-squared and be no higher than 3m above ground level.
  • No part of the porch should fall within two metres of the boundary of the original property and the highway. 

Your Permitted Development rights

Permitted Development rights only apply to private houses, flats and listed buildings are excluded. Properties in specially designated areas such as Conservation Areas or on a green belt are also subject to further restrictions.

Permitted Development rights can be used as often as you like but allowances for extension work can be used only once. If you are buying a property it is your responsibility to find out what Permitted Development rights may have already been used, modified or withdrawn.

In most cases it is possible to determine if your project can qualify as Permitted Development, there may be instances where you need to seek further advice. Rather than submit a planning application, applying for a Lawful Development Certificate may give you the answers. This is a formal application for your local authority to decide if a project requires planning consent or not.

Before any work begins, you should contact your local planning office and discuss your project.

Useful Links 

Useful Government Website for information on Planning Permission

Planning Portal

Government Building Regulation Information Site

Building Regulations