What do you need planning permission for?

Making changes to your home can be exciting. Moving or remodelling a bathroom, creating an extra room with an extension, or giving the garden a makeover with new decking and a summer house for example – there are lots of possibilities.

​What is planning permission?

Planning permission is a process you need to go through for certain home improvements and involves asking the local council if you’re able to make the changes.

They will check if your plans are suitable and won’t cause any problems. As part of this, they will also ask your neighbours for their opinion. If you own a listed building and are looking to extend or alter you will also need to obtain listed building consent. Only once permission has been granted can you begin the identified work.

When do you need planning permission?

Where planning permission isn’t required, this is known as ‘permitted development’.

The information in this article is correct as of November 2024 for planning permission in England. The regulations may differ if you live in Scotland, Wales or Northern Ireland. Always check with your local council if you’re unsure about whether you do or don’t need planning permission.

Flats and maisonettes are excluded from permitted development rights. To understand what extension options are available for these types of property, please consult either your local council or a qualified architect. 

Do you need planning permission for an extension?

Whether you need planning permission for an extension mainly depends on the size of the extension, where it will sit in relation to boundaries and the materials that will be used.

In general, you’re likely to need planning permission if:

• Your extension takes up more than 50% of land around the "original house"  (the original house is how the property was in 1948 or after this date, how it was newly built)
• If you’re extension extends beyond the rear wall of the original house by more than 8 metres (detached homes) or 6 metres (semi-detached and terraces).
• Your extension is taller than 4m in height and has eaves that go past the existing house.
• The new addition doesn’t match the style of the existing property and uses different materials.
• Your house sits on designated land – this is land that sits on or within a conservation area, a place of outstanding natural beauty, a World Heritage site or a National Park.

For all extensions, you check the exact rules with your local council before assuming that you do or don’t need planning permission.

Do you need planning permission for a conservatory?

A conservatory will need to meet the same design criteria as listed for an extension above. You will also need planning permission for a conservatory if:

• You live on designated land and the conservatory will be built on the side of the property
• You live on designated land and the conservatory will be cladded with stone, pebble dash, timber, plastic, tiles, artificial stone or render
• You plan on building a side conservatory that will be taller than four metres, or taller than three metres when closer than two metres to a boundary.

As long as your conservatory meets the rules set out under the extension section and none of the above points apply, then it is likely your conservatory will fall within permitted development and you won’t need full planning permission.

Do you need planning permission for a loft extension?

You may need planning permission for a loft extension in England if:

• You want to add more than 50 cubic metres of additional roof space for detached and semi-detached houses (40 cubic metres for terraced houses)
• Your loft extension doesn’t use similar building materials to the existing house
• The development includes a window in any wall or roof slope forming a side elevation 

The rules around loft conversions and extensions can be confusing, so do visit the Planning Portal website for all the information.

The Planning Portal was established by the UK Government in 2002 and is the home of planning and building regulations information and the national planning application service for England and Wales.

It’s worth noting that a loft conversion is different to that of a loft extension, and so if you’re not altering the size of the loft, you may not need planning permission. You might, however, require a building inspection upon the completion of work to ensure it adheres to Building Regulations and is signed off.

Do you need planning permission for a porch?

The planning permission rules for porches are a little simpler than extensions and conservatories.

Porches may need planning permission, if your designs fit the below: 

• The ground floor area (measured externally) exceeds 3 square metres
• A part of the porch is more than 3 metres above ground level 
• Some part of the porch is within 2 metres of any boundary of your home and the main road

Do you need planning permission for a shed?

A shed is considered an outbuilding, which, according to Planning Portal, also includes garages, greenhouses, playhouses, saunas, summer houses, kennels and even swimming pools. This means, for all of these structures, the planning regulations are the same.

An outbuilding, you may need planning permission if:

• It is taller than 4 metres (if it has a dual-pitched roof) or 3 metres for any other type of roof
• You want to add a veranda, balcony or raised platform
• It takes up more than half the land of the original house, other outbuildings (such as sheds) should be added to the total too
• You plan on using your outbuilding for residential purposes

Many standard sheds won’t require planning permission. However, before installing, you should check that the height will fall within the above limits.

Remember: Listed buildings and homes in designated land have different rules, so check with your local council before any changes are made to these types of homes. 

Do you need planning permission for a summer house?

A summer house counts as an outbuilding, which means the same rules apply as they do for a shed above.

Do you need planning permission for a pergola?

Pergolas also count as outbuildings, and so the same rules also apply as above for sheds.

Do you need planning permission to convert a garage?

Planning permission is not usually required, providing the work is internal and does not involve enlarging the building.

If your intention is to convert a garage into a separate house (regardless of who will occupy it), then planning permission may be required no matter what work is involved.

We advise that you discuss such proposals with your local planning department to ensure that any work you do is lawful and has the correct permissions.

Do you need planning permission for decking?

You may need planning permission for decking and other raised platforms if:

• The total height will be more than 30cm above the ground
• The total area covers more than 50% of the garden area, together with extensions and outbuildings

Do you need planning permission for solar panels?

Solar panels are usually considered permitted development and so it’s very rare that you will need to apply for planning permission prior to installation.

If you’re unsure or believe your circumstances differ to those of a regular property, you should contact your local council and discuss your situation and requirements.

Seek confirmation from your local council 

Some of the planning elements are very specific, especially when it comes to large changes to your home, such as extensions, conservatories and outbuildings. If in doubt, you should always confirm with your local council the changes you want to make, and they will advise whether they fall under permitted development or not.

Summary

If you’re looking to extend or renovate your home and want to know if you’ll need planning permission, keep these key points in mind:

• There are a variety of projects that don’t require planning permission, which fall under your ‘permitted development rights’.
• Some properties, such as flat or listed buildings, have their own design rules and may need extra consideration.
• Small projects, such as adding a new shed or solar panels, tend not to need planning permission – but there are exceptions.
• The best thing to do is talk to your local council, whose planning team will be able to a offer tailored advice.