The idea of getting planning permission is enough to strike fear into the most ambitious home improver. Everyone has heard horror stories of unfathomable processes, rejections and delays. But it doesn’t need to be frightening. Many home improvement projects don’t need planning permission at all. It all depends on where you live and what you want to do.

It is important to find out if you need planning permission. Work carried out without the necessary permission can be a criminal offence. In the most serious cases, planning authorities can force property owners to undo the work they have done and restore buildings to their former state.

There are specific rules for listed buildings and conservation areas (see below) but most homeowners will typically need planning permission if they want to:

  • Build something new
  • Make a substantial change to their building
  • Change the use of their building

Which? Trusted Traders has endorsed builders and contractors who will be able to help with your planning and renovation projects. 

Here’s a more detailed breakdown of when most homeowners do and do not need planning permission - this list does NOT apply to listed buildings or those in conservation areas:

Extensions and Conservatories

An extension to your home is typically a ‘permitted development’, so you won’t need planning permission, as long as:

  • The extension is no more than half of the area of the land around the original house as it was in 1948 or, if built later than 1948, when it was new.
  • It is not in front of the principal elevation or side elevation onto a highway. This means you can’t extend out into your front garden without planning permission, or to the side of your house if these sections of garden are next to a road or pavement.
  • It is not higher than the highest part of the roof.
  • The extension does not go more than three metres past the rear wall of the original house (or four metres for a detached house if it is only a single storey).
  • Single storey extensions are not more than four metres high.
  • Side extensions are single storey only with a maximum height of four meters and a maximum width of no more than half of the original house
  • Two storey extensions must be at least seven metres away from the rear boundary of the property.
  • The materials are similar in appearance to the existing house.
  • The extension does not include verandas, balconies, or raised platforms.
  • Any upper-floor, side-facing windows are obscure-glazed.

If you want to build an extension or a conservatory that goes beyond any of these restrictions, then you will have to get planning permission from your local authority.

Garages, sheds, and other outbuildings

Garages, sheds, greenhouses, and other outbuildings are also ‘permitted developments’ and you are free to build them without planning permission as long as they are no more than four metres high and do not take up more than half the land around the original property.

Paving over the front garden

If you are paving over the front garden with a porous material, you do not need planning permission, regardless of the size of the project.

If you are using impermeable material like concrete, tarmac, block or flag paving however, you will need to apply for permission for anything over 5 square metres.

Windows and doors

Typically, you do not require planning permission to repair or replace windows or doors.

External walls and roof

You do not require planning permission for maintenance works or improvements, such as painting your house or adding a skylight.

Wind turbines and solar panels

Temporary wind turbines do not usually require planning permission but permanent ones usually do. You will not typically need planning permission for solar panels.

Fences, gates, and walls

You will only need to obtain planning permission for a gate, fence, or wall, if it:

  • is over 1 metre high and located next to a road
  • is over 2 metres high in any location
  • forms a boundary with a listed building.


The majority of internal works, such as loft conversions, garage conversions, new staircases, bathrooms, kitchens, and rewiring do not require planning permission.

Listed Buildings

Buildings on the National Heritage List for England are considered of special architectural or historic interest and have additional protection in the planning system. Most types of work will require Listed Building Consent from your local authority and listing can affect outbuildings on the property as well. It is best to check the details with your local planning authority before planning any work internally or externally.

Conservation areas

Conservation areas exist to protect the historic and architectural elements that made them special in the first place. This means that there may well be specific controls that affect work to the exterior of your property and any trees on your property. This can restrict work like replacing windows or doors or altering gutters and downpipes. Again, you will need to contact your local planning authority for the precise details of the work that is covered.

Whatever the building work you are planning to carry out it’s always worth consulting a professional - either your builder or your local council. If in any doubt contact your Local Planning Authority or visit the Planning Portal for further details.

Which? Trusted Traders endorsed builders will also be able to assist you with your planning queries and applications.

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