Permitted development is the term used to describe the works you are allowed to do without the need for planning permission (under article 3 of the General Permitted Development Order (GPDO)). There are various criteria which you must meet in order to benefit from this. If you live in a house, you can make certain types of minor changes to your home without needing to apply for planning permission. These are called 'permitted development rights'.
Permitted development restrictions
Your permitted development rights may be restricted (under article 4 of the GPDO) if you live in a conservation area. You will need to apply for planning permission for certain types of work which do not need an application in other areas.
Article 4 directions are made when the character of an area of acknowledged importance would be threatened. They are most common in conservation areas. You will probably know if your property is affected by such a direction or other restrictions, but you can check with the council if you are not sure.
There are also different requirements if your house is a listed building.
Have your permitted development rights been removed?
The council may have removed some of your permitted development rights when permission was given for the original development, or by issuing an article 4 direction.
This will mean that you have to submit a planning application for work which normally does not need one.
Information on permitted development is available from the Planning Portal website link on the 'Other websites' section of this page.