Prior approval is a procedure attached to certain permitted development rights in England. It is not an alternative application that you can choose for any project. The development must qualify for the specific right, and its procedural requirements must be followed.
When do home extensions need prior approval?
The larger home extension route covers qualifying single-storey rear extensions projecting more than 4 metres and up to 8 metres from an original detached house, or more than 3 metres and up to 6 metres from other original houses. Other eligibility limits still apply.
The council consults adjoining neighbours. An objection triggers consideration of the extension's effect on neighbouring amenity; it does not itself decide the outcome. Read the Planning Portal's larger extension procedure alongside our rear extension guide.
Does every prior approval application follow the same rules?
No. Different rights specify different matters for assessment, exclusions and deadlines. A commercial conversion should not use a larger home extension checklist. The government's planning route guidance explains the distinction; our change of use guide helps you describe a conversion proposal.
Do not treat silence from the council as universal permission to start. Establish the applicable procedure, submission requirements and legal position before relying on a deadline.
What should you prepare before applying?
Make a short record of the right being considered, the proposed dimensions, the original building and earlier additions. Keep a separate list of any eligibility questions still unresolved. This makes it easier to distinguish a design problem from a missing document.
Find your planning authority and check its application instructions. Save the submitted drawings and correspondence together, including the council's acknowledgement and eventual decision. If the design changes, establish what that means for the application before replacing drawings or starting construction.
Is a lawful development certificate the same thing?
A lawful development certificate confirms lawfulness; it does not bypass a required prior approval procedure. Start with the permitted development checker if you are unsure which route to investigate.
Before commissioning work, also compare the application costs and decision timescales. Agree the scope of drawings, submission work and any additional reports rather than assuming every prior approval proposal needs the same package.