Adding an extension to your house can be a great way to make more space. Whether you're looking to extend your kitchen, build a bigger living area, or add another bedroom, it’s important to know the rules before you start. One of the most important questions is: do I need planning permission for my extension?
What Is Planning Permission?
Planning permission is the approval you may need from your local council before building something new or changing the use of a building. It helps make sure that any changes fit in with the area and don’t cause problems for your neighbours or the environment.
You must apply for planning permission if your building work goes beyond what’s allowed under general rules. The council looks at things like size, height, shape, and how close the project is to other buildings or roads.
When You Might Need Planning Permission
You might need permission if the extension is large, goes above a certain height, or changes the front of your house. You’ll also need it if the extension is very close to a road or boundary, or if you live in a listed building or conservation area.
If you're planning a double-storey extension, a wraparound extension, or building something that covers a large part of your garden, you will likely need to apply. The same goes for changes in the use of a building, such as turning a garage into a living space.
Even if you think your project is small, it’s important to find out if permission is needed before you build. A quick check can save you lots of trouble later.
Permitted Development Rights
Some types of extensions can be built without planning permission under what are called permitted development rights. These rights allow homeowners to build certain types of extensions as long as they follow strict rules.
For example, you can often build a single-storey rear extension that does not go back more than 3 to 6 metres, depending on the type of house. Side extensions are allowed too, but only if they are small and don’t change the shape of the house too much.
Permitted development rules don’t apply in all areas. If you live in a flat, a listed building, or in some newer housing estates, these rights may not apply. It’s always safest to check with your local council.
How to Apply for Planning Permission
If your extension needs planning permission, you’ll need to apply before starting any building work. You can do this online through the Planning Portal.
You’ll be asked to send drawings, explain how the extension will be used, and give details of the work.
Many people choose to work with extension builders or an architect, who can help with plans and paperwork. The council usually decides within eight weeks. You should not start building until you have written permission.
What Happens If You Don’t Get Permission?
If you build without the right permission, your local council can ask you to remove the extension. This is called enforcement action. You could also be fined or face delays if you try to sell your house later.
To avoid problems, always check what permissions are needed. If in doubt, apply before you build. Asking your builder or council for advice is a good first step.
LBH Building And Property Services are trusted extension builders serving Welwyn Garden City, Hertford, St Albans, and nearby areas. Whether you're planning a home extension or need expert advice on your project, we're here to help every step of the way. Get in touch with our team to see how we can bring your plans to life.
