Do You Need Planning Permission for Your Home Extension in the UK?

Written By shaun cudworth

Extending your home is one of the most popular ways to add space, value and comfort to your property. However, one of the first questions homeowners face is: Do I need planning permission?

The answer isn’t always straightforward - it depends on the size, location, and design of your extension. Understanding the difference between planning permission and permitted development can save you time, money, and frustration.

What is planning permission?

Planning permission is legal approval from your local council to carry out certain types of building work. It ensures that developments are appropriate for the local area, don’t negatively impact neighbours, and align with broader planning policies.

If your project significantly alters the appearance, size, or use of your property, planning permission is usually required.

What is permitted development?

Many home extensions fall under permitted development rights, meaning you can proceed without submitting a full planning application - as long as your project meets specific limits and conditions.

Common permitted development allowances include:

  • Single-storey rear extensions up to a certain depth

  • Extensions that don’t exceed the height of the existing roof

  • No extension forward of the principal elevation

  • Use of materials similar to the existing property

However, permitted development rights are not automatic.

They can be restricted in:

  • Conservation areas

  • Listed buildings

  • National parks

  • Areas of outstanding natural beauty

  • Designated heritage zones

If your home is in any of these areas, you may need planning permission even for a small extension.

How do you check what applies to your home?

A sensible first step is to speak to a professional before committing to designs or builders.

At License To Build, we help homeowners assess:

  • Whether their project qualifies under permitted development

  • Whether a lawful development certificate is needed

  • Whether full planning permission is required

  • What documentation and drawings will be necessary

This early-stage guidance helps you avoid costly redesigns or enforcement issues later.

Why getting this right matters

Proceeding without the correct permission can lead to serious consequences, including:

  • Council enforcement action

  • Fines

  • Being required to remove or alter your extension

  • Problems when selling your home

A well-planned extension should enhance your home, not create legal headaches.

How License To Build supports you

We take the stress out of the planning process by:

  • Reviewing your property and its planning constraints

  • Advising on realistic design options

  • Preparing planning drawings where needed

  • Working alongside architects, planners and builders

Our goal is to make your extension journey clear, compliant, and successful from day one.

If you’re considering an extension, get in touch with License To Build to understand your options before you start.

shaun cudworth