How much does it cost to get planning permission for an extension

If you’re about to apply for planning permission to get started on your extension or renovation project, or are wondering how fees have changed over the years, worry not!

Our in-house planning team are here to give you the lowdown on all the costs associated with the planning stage of your project.

How much does planning permission cost for an extension?

Costs for planning permission differ, depending on where you are in the UK. To extend your home, you’ll be looking at…

• £206 within England
• £230 in Wales
• £300 in Scotland

These costs apply to alterations / extensions to existing dwellings, and only for one household. So whether you’re going for a classic rear extension, or converting your loft, these are the fees you’ll be paying.

However, if you’re taking on a self build project, costs rise to £462 per new dwelling in England, and £460 in Wales, £600 in Scotland.

All these costs relate to a full planning application, fees will vary for outline planning permission applications. Outlines are often used on large projects to give the developer an idea of what might be possible before an architect is brought in to provide the details.

Please note: outline planning permission cannot be used to start construction.

Cost of full planning application in the UK: recap

Note: Planning application fees are likely to be increasing at the start of 2024.

Do you need planning permission?

Now, before you get your checkbook out, it’s worth noting that not all extensions require planning permission.

Your home might benefit from your permitted development rights. These are part of a government scheme that allows homeowners to extend their home without the need for planning permission. However, there are strict rules about what kind of developments fall within your permitted development rights.

In order to avoid a full planning application, you’ll need to ensure your extension…

• Doesn’t extend beyond the rear of the existing house by more than 4 metres, if your home is detached, and 3 metres, if you live in a terrace, or semi-detached property. Unless you're using the Larger Home Extension scheme.
• Only takes up less than 50% of the size of the land around the original house ("original" being the latest of when the property was built or if it was built before 1948, then as it stood on 1st July 1948).
• Is single-storey, with a maximum height of 4m.

• Had a roof ridge or top point no higher than the eaves of your property’s roof.

Learn more about permitted development here.

On top of this, you’ll need to bear in mind that permitted development rights can’t be used on these households...

• Listed buildings
• Flats or maisonettes
• Some new developments

Homes from conservation areas are not excluded from permitted development rights, however they do hold much greater restrictions.

It's also worth noting, certain homes and areas have not been included in the 2020 extension of permitted development rights. These are...

• Homes within Scotland, Wales, or Northern Ireland
• Homes built before 1948

In these cases, you'll need to apply for a full planning application if you want to create additional storeys or build a larger rear extension.

What are the other costs related to planning permission?

What is prior approval?

While permitted development rights allow you to build without undergoing a full planning application, the new projects introduced by the 2020 changes will require your local planning authority to assess them. This process is known as ‘prior approval’.

Projects which require prior approval…

• Adding additional storeys
• Larger rear extensions

Prior approval allows your local authority to assess whether your designs meet the strict guidelines and measure your project’s impact on the surrounding area, such as nearby transport and highways.

Time required: on average it takes 8 weeks to assess an application.
Fee: roughly £100 for a single extension onto an existing dwelling.

© Matt Gamble

What is a lawful development certificate?

The certificate essentially proves to both your local authority and future buyers that your project was legal at the point of construction. This protects you in the event any planning policies change.

Even though this certificate isn’t a legal requirement, we recommend it for everyone using their permitted development rights (excluding those require prior approval).

If the legislation for permitted development on your project aren’t clear cut, or it has been conditionally withdrawn in your area, you should definitely apply for a lawful development certificate or may even need to submit a planning application.

Time required: on average 8 weeks.
Fee: £103 in England, £85 in Wales, and £101 in Scotland.

What some tailored planning advice for your home? Book a free consultation with Resi. We’ll assess your project and lay out your options, all free of charge. We also have our own in-house planning team, so should you choose our services, we’ll even be able to submit your application on your behalf.