The planning rules covering extensions are explained in this section on the Planning Portal. You may also find this interactive guide to Extensions useful, which illustrates visually what is covered in our text guidance. (The interactive guide needs Adobe Flash to be installed on your computer. You can download Flash free-of-charge from the Adobe website.) If, after using our site guidance, you have further questions about a particular aspect of planning permission you should contact your local planning authority, usually your council. Our Service Desk aren’t planning experts so you will need to talk to your local authority planning team. You can find contact information for your local planning authority on the Planning Portal.