A Look at “Permitted Developments” in the United Kingdom

Discover what home improvements you can undertake without the need for planning permission from your local authority.

This page is all about “permitted developments” in the United Kingdom, what you can and can’t do.

What Are Permitted Developments?

Permitted development rights allow you to extend, alter, or change your home’s use without the need for planning permission, provided the work is done according to strict criteria set out by the government.

If you’re unsure of your rights, it pays to get professional advice. Some councils offer a consultancy service for a small fee, chartered surveyors can also advise you of whether your plans fall within the permitted development rules.

Permitted development rules only apply to houses, not flats, maisonettes or other buildings.

Listed Buildings

If your property is a listed building, you may still need listing building consent, even if the proposed work falls under permitted development rights.

Building Regulations

Planning permission and permitted developments are separate from the building regulations which typically cover the safety and performance of building materials and construction techniques.

Why Is The Government Relaxing The Planning Permission Rules?

There are several reasons why the government is making it easier for homeowners to extend or alter their homes:

  1. to reduce the number of costly applications local councils have to consider.
  2. to encourage homeowners to maximise the living space within the boundaries of their own property.
  3. to make it easier for developers to convert offices and business premises into domestic homes.

Can Everyone Benefit From the Permitted Development Rights?

The rules dictate how far and high you can extend your home but if your property has already been extended, this will count towards your permitted development allocation.

You cannot extend over and over again to dodge the traditional planning permission route.

The total area extended must not exceed the allocation, if it does, you’ll need to get full planning permission.

How Far and High Can I Extend?

Below is an introductory guide to permitted development rules as set out by the government.

These rules are updated periodically so do check with the Planning Portal website for the most up to date information available.

Single Storey Extensions Via Permitted Developments

You can extend up to 8 metres in depth if your home is detached and the extension is a single storey.

This is reduced to 6 metres for semi-detached and terraced homes.

If the extension is within 2 metres of a boundary, the height of the eaves must be no higher than 3 metres, otherwise 4 metres.

There are strict conditions that must be adhered to:

  • must not be a front extension (unless it’s a small porch not greater than 3 square metres)
  • a side extension must not face a highway
  • side extensions must not be greater than 50% of the total land area around the original building
  • rear extensions must not occupy more than 50% of the total land area around the original building
  • the roof must not be higher than the original ridge on the home

Double Storey Extensions Via Permitted Developments

Double-storey extensions can only be constructed in the rear garden if you want to avoid full planning permission.

The build must not extend more than 3 metres from the original building and must not be closer than 7 metres from the boundary.

The angle of the roof must be similar to that of the existing roof and the overall height of the extension must not be higher than the existing building.

Side facing windows on the first floor should be obscured to protect the neighbour’s privacy.

The extension, including existing extensions and any outbuildings/sheds etc should not exceed 50% of the original garden when the home was built.

Read our guide to house extension prices here.

Loft Conversions/Extensions

You can convert your loft space into a habitable room without applying for planning permission, provided that:

  • you do not install a dormer to the front aspect, although Velux style roof windows are acceptable.
  • rear aspect dormers must not exceed the original height and depth of the existing building.
  • no dormer shall face a highway.
  • the maximum loft conversion size is 50 sqm for detached houses and 40 sqm for semi-detached and terraced homes.

Explore our popular guide to loft conversion prices and costs here.

Garage Conversions Under Permitted Development Rights

In most cases, you can convert an integral garage into a habitable room under permitted development rights, however, the Planning Portal has published this warning:

Sometimes permitted development rights have been removed from some properties with regard to garage conversions and therefore you should contact your local planning authority before proceeding, particularly if you live on a new housing development or in a conservation area.

Detached garages will normally need full planning permission consent if you want to convert it into a separate house, regardless of who lives in there.

How much does it cost to convert a garage?


Under the permitted development rules, you can construct a porch or porch canopy provided that:

  • it’s not greater than 3 sqm in size (measured externally at the ground level).
  • not less than 3 metres from a boundary or highway.
  • must not be taller than 3 metres.

See how much it costs to add a porch here.

The Planning Portal

The planning portal website was created by the UK government and is the best place for the most up to date information. You’ll find interactive guides and project helpers.

Explore the planning portal here.

Get a Price Today