Do you need planning permission for a home extension?

Building a house extension is a perfect way to increase your house value, get some extra space and avoid moving to a bigger property. Whether you decide to go up or extend to the garden, there are many ideas you can use to maximise the use of the extension. However good your idea is, there are some things you have to remember and getting a legal permission to extend is one of them. When do you need planning permission for a home extension and when is it acceptable to change your house layout without it?

When do you need planning permission in the UK?

Any addition or extension to your own property is considered legal, as long as it complies to following rules:

• If the size of the extension is not bigger than half the size of your land surrounding the original house, an extension can be built without a planning permission. It’s worth knowing, however, that if the house was previously rebuilt or extended, you will be required to get a permission.
• No extension can be higher than the highest part of the roof, which means that if you want to go up with an extra floor, a planning permission will be required.
• Most people extend to the garden. If that’s your plan, by law, single-storey rear extensions can’t extend beyond the rear wall of the original house by more than three or four metres (for semi-detached and detached house accordingly) if you want to build without planning permission.
• Side extensions, built in the side garden rather than back must be single storey, with maximum height of four metres and width no more than half that of the original house for no permission to be required.

If you decide to build an extension to your house, you must use materials that are similar to those used for the original house. Anything that would clearly distinguish the extension from the house visually means that you have to get planning permission before you start the build. It’s also worth remembering that conservatories, which are very popular way to extend the house are subjected to the same rules mentioned above.

What can you do without any permission?

Getting a planning permission where it is necessary can’t be skipped by – if you decide to change things you are supposed to get a permission for, you can be served an enforcement notice ordering you to undo all the changes that were made and bring the house to its original state. There are, however, some things you can actually do without having to apply for a planning permission.
All the rules mentioned previously mean that you can actually build a lot without planning permission, but you must be very careful while planning the build and make sure the plans comply to all of them. Similarly, builds like garages, sheds and other outbuildings are generally considered to be permitted development and don’t require getting a planning permission if they are reasonably sized, which means not higher than four meters and not taking more space than half of the land around the original property. No planning permission is necessary for indoor renovations.
In order to make sure that planning permission is not necessary for a planned extension to your house, it’s worth consulting your Local Planning Authority.