Permitted development is a national grant of planning permission. It allows for smaller developments to be made to your home without the need for a planning application.

If you are planning on improving your home, you could save time and money by amending your plans to ensure the work falls under permitted development rights. You might be surprised just how much you can do without applying for planning permission.

What is covered by permitted development?  

Permitted development only applies to houses. Flats, maisonette and other buildings are not covered by permitted development. Any work carried out is subject to planning permission. Commercial buildings also have a separate set of permitted development rights.

There are a number of improvements that can be made to your home under the Permitted Development rights. You could:

  • Convert your loft
  • Add a porch
  • Change your internal layout
  • Install solar panels
  • Put in rooflights or add dormer windows (unless they face the road)
  • Put in new doors and windows
  • Convert your garage
  • Construct a new driveway, provided you use a porous material, or install drainage if using non-porous materials
  • Build a small extension
  • Add an outbuilding to your land. It cannot cover more than 50% of your garden with a maximum height of 4m for a pitched roof or 3m for a flat roof.

Importantly, there are strict constraints that must be conformed to for work to fall under permitted development rules.

For an in-depth explanation of Permitted Development Rights, visit the GOV.UK website or Planning Portal.

For the sake of this article we will look at the constraints for building an extension.

Building an extension

  • Extensions and other buildings (including sheds) cannot exceed 50% of the total area of land around the original house. If the previous owner had built an extension, this takes up part of the 50%.
  • The materials you use on your extension must be similar to those used on your house for it to fall under permitted development rights. Unless it is a conservatory.


  • You cannot build an extension on the front of your house, if facing a road, under permitted development.
  • Side extensions can be single storey only. They should be no wider than half the width of the original house. And be no taller than 4 metres. Unless it is within 2 meters of a boundary, in which case it should only be 3 metres
  • Extensions at the back of the house must not extend further than 6 metres on an attached house. Or 8 metres on a detached house. And be no taller than 4 metres.
  • The maximum eaves and ridge height shouldn’t be higher than the existing house. 


  • Multi storey extensions are not permitted on homes in designated areas.
  • Extensions of more than one storey must not extend beyond the rear wall of the original house by more than 3 metres or be within 7 metres of any boundary opposite the rear wall of the house.
  • Roof pitch of extensions higher than one storey must match the pitch of the existing house. They can be no higher than the existing house. If the extension is within 2 metres of a boundary, the maximum height of the eaves cannot exceed 3 metres in height.
  • Upper-floor windows that face out of the sides of the extension must be obscure-glazed. They should not open unless the part which opens is more than 7 meters above the floor of the room in which it is installed.
  • You cannot have a balcony or veranda under permitted development.

Are there any other restrictions?

Always check with your Local Planning Authority before you begin any work. There are cases when Permitted development has been removed or is restricted. This could be because of the area you live in, if your building is listed or if you have already made numerous improvements to your home.

Permitted development rights are far more restricted in ‘designated areas’. This could mean you will need planning permission for development that is permitted elsewhere.

Designated areas include:

  • Conservation Areas
  • National Parks
  • Areas of Outstanding Natural Beauty
  • World Heritage Sites
  • The Norfolk or Suffolk Broads.

How do you know if your planned development meets the guidelines?

Sometimes, it’s not clear whether work is covered by permitted development rights. In this case it is recommended that you consult with a qualified surveyor or your local planning authority.

Prove it with a Certificate of Lawful Development (CLD)

You can also apply for a Certificate of Lawful Development. A CLD confirms, in writing, that planning permission was not required. This is particularly useful if you are expecting to sell your house in the near future. You need to provide proof that any work done was within the permitted development rules.

Remember, all work carried out will still need to comply with all relevant building regulations.

Here at JS Building Services, we want to make sure that you go confidently into any project that you undertake. That is why we offer a consultancy service. Whether you are after some advice about planning permission or an experienced professional to help with the execution of your project. We can help. Get in touch today and discuss your project with us.