You can sometimes extend your property without the need for planning permission. This is called "Permitted Development".
This only ever applies if you live in a house or bungalow, not flats, maisonettes or houses in multiple occupation.
Sometimes a condition has been placed on the original approval for the house that does not allow this.
You can check using our online planning map to see if your property has its Permitted Development allowances removed. Once the map has loaded you will need to tick the 'Constraints' box on the map legend.
Areas of No Permitted Development will be marked with blue hatched lines.
If your property has Permitted Development allowances these links will help you to decide if your proposal needs planning permission.