Local authorities are meant to decide planning applications within eight weeks of registration. Most straightforward home extensions will be dealt with within this timesale. During this period, planning officers advertise the application and consult neighbours and statutory bodies such as the Highways Authority or Environment Agency. They are also likely to make a site visit.

But all the reports, surveys and detailed drawings in the run-up to submitting the planning application means the whole process can take a lot longer. Months even years in a few cases. It all depends on the size and sensitivity of your project and the amount of preparation required.

How will I be told?

Once you have submitted a planning application you will be sent a letter from your local planning department acknowledging receipt of the form and fee. This letter will also highlight the stages through which the application will pass before a decision is made.

At the end of the process, a decision notice will be issued advising whether planning permission has been granted or refused.

If you have employed an agent to work on your behalf, such as an Architect, all correspondence will be sent to them. If not, the department will contact you directly.

What if my planning application is refused?

In England, three-quarters of planning applications are approved. But if your project is refused, reasons will be given, so you can amend the plans and resubmit. If you didn’t use a local Architect or Planning Consultant first time round, you may consider employing one now. They can’t guarantee to win planning consent, but it will increase your chances of success. There is also the option of appealing to the Planning Inspectorate to review the council’s decision. But this is a very expensive route, potentially costing thousands of pounds.

Can I alter my plans once full permission has been granted?

Major alternations such as adding bedrooms or changing the roof pitch could lead to a further planning application. But minor alternations, such as moving a door a few centimetres, may be considered negligible or “deminimalist.” Other minor issues may be dealt with by applying for a non-material amendment. For bigger changes, you can apply to have planning conditions altered.

How long does planning permission last?

Generally, unless your permission says otherwise, you have three years from the date it was granted to begin building your home extension. If you haven't started work by then, you will probably need to reapply.