Permitted Development for Dwellings
Here you can find information about works you can do to your house or within the curtilage of your house.
That are certain things you can do that do not require planning permission, however, there are many rules that control this. This is known as permitted development. Planning permission will be required for works to your house if the work is not permitted development. You find guidance on the planning portal on common projects and when planning permission may be required.
Even if the work is classified as permitted development, you may still need planning permission as some properties do not have permitted development rights. You can find out if permitted development rights have been removed by carrying out a planning history search.
A Lawful Development Certificate for Proposed Development can provide a legally binding determination that permission is not required. This will require all the plans that an application for planning permission would require and for householder development, a fee is applied.
Building Regulations
Building Regulations Approval is also needed for many types of development. This is separate to planning permission. You should check with Building Control to find out whether Building Regulations Approval is needed for what you want to do.