What is it?
Planning Permission is required to stop people affecting the stability of a building, creating a health or fire hazard or affecting the surrounding area. For example, if you plan to remove a load-bearing wall to open up a room, planning permission will be needed, as this will affect the structural integrity of the building if not done correctly.
When do you need it?
Every property (apart from listed buildings) has an allowance called Permitted Development. This states that the owner can increase the size of the house by up to 40 cubic metres (or 10% of the total size) before planning permission is needed. However, this includes any developments made by previous owners. If your house is the only one in the street with a garage, it is likely that your permitted development has already been used up and you will need to apply for planning permission. Here are a few situations where planning permission is needed:
Removing load-bearing walls
Adding a window or door to an exterior wall
Installing a new heating or plumbing system
Installing a new bathroom (where plumbing will be changed from the existing layout)
Moving a staircase or changing the height of a room
If your home is a listed building or is located in a preservation area (you may need permission even to change the colour of your front door in such cases)
This is by no means an exhaustive list; so if you are in doubt, check with your local council planning office
How to apply
Your first port of call should be to your local council planning office. They can offer advice as to whether you need to also contact the Building Inspectors office in London. Planning permission applications currently cost £100 and you may need to provide detailed plans and drawings of proposed works. If you cannot provide these yourself, you will be required to employ someone to do them for you. Your planning application will then be made public for 21 days to allow anyone to make objections (unlikely unless you are going to be blocking someone’s view, etc). If only two objections are made, the application will have to be seen by a committee, who will decide if you can or cannot go ahead. They may also allow you to go ahead provided you make some changes they will propose.
Other things to remember before work starts
Even if you think you don’t need planning permission, there are a few cases where you will still need to seek permission before altering a property.
1. Some older houses are subject to restrictions imposed by the original landowner. This does not happen very often, but it is worth checking before adding that extension.
2. If your house is not a freehold property, you will need to check with the freeholder before carrying out any work.
You can find out more about planning permission at the Planning Portal