Prior Approval vs Planning Permission: What’s the Difference?

Prior approval is a simplified application process that applies to certain types of permitted development. The development itself is already granted permission by the GPDO, but the council has the right to assess specific impacts before work begins.

The council can only consider the matters specified in the GPDO for that class of development. They cannot refuse prior approval on general design, planning policy, or amenity grounds beyond what is specified.

If the council does not respond within the specified time period (usually 42 days), prior approval is deemed to have been granted.

Planning permission is a full application to your local council for permission to carry out development. The council assesses your proposal against the National Planning Policy Framework, local plan policies, and any material planning considerations.

The council can consider a wide range of factors including design, appearance, impact on neighbours, traffic, ecology, heritage, and more. They consult neighbours and statutory consultees.

There is no deemed approval if the council does not respond in time — you can only appeal against non-determination.

Prior approval is required for certain types of permitted development where the government has decided the council should have some oversight. The most common scenarios for homeowners are:

• Larger Home Extension (Class A, paragraph A.1(g)) — single-storey rear extensions between 4–8m (detached) or 3–6m (semi/terrace)
• Additional storeys (Class AA) — adding one or two storeys to a dwelling

Prior approval also applies to various non-residential PD classes (office-to-residential conversions, agricultural-to-residential, etc.) but these are less relevant to typical homeowners.

1. Submit the application — complete the form and provide plans showing the proposed development, along with a written description of the project
2. Pay the fee — £249 for Larger Home Extensions
3. Council notifies neighbours — adjoining owners are notified and have 21 days to comment
4. Council makes a decision — within 42 days, the council either grants prior approval, refuses it, or does not respond (deemed approval)
5. Start work — if approved (or deemed approved), you can proceed

The council can only consider the impact on the amenity of adjoining premises for Larger Home Extensions. They cannot refuse on design, appearance, or planning policy grounds.

Prior approval is the cheapest route for extensions that exceed standard PD limits. If your extension is within standard PD limits, you may not need any application at all (though an LDC is recommended).

Yes, but only on the specific matters the council is entitled to assess. For Larger Home Extensions, the council can only refuse if the extension would have an unacceptable impact on the amenity of adjoining premises.

Common reasons for refusal include:

• Overlooking — the extension would create significant loss of privacy for a neighbour
• Loss of light — the extension would significantly reduce daylight to a neighbour’s habitable rooms
• Overbearing impact — the extension would be so large relative to a neighbour’s property that it creates an oppressive effect

If prior approval is refused, you can appeal to the Planning Inspectorate or apply for full planning permission instead.

If your prior approval application is refused, your options are:

• Appeal — you can appeal to the Planning Inspectorate. Appeals are free and decided on the limited grounds that the council was entitled to consider
• Reduce the size — bring the extension within standard PD limits (4m detached, 3m semi/terrace) to avoid needing prior approval entirely
• Apply for full planning permission — the council then assesses the full merits, which may actually work in your favour if the design is high quality. The fee is £548