Prior approval deadlines across the permitted development classes

Prior approval periods are not all 56 days. A larger householder extension runs on 42 days, agricultural buildings under Part 6 turn on 28 days, demolition notification under Part 11 is 28 days, and the change of use classes in Part 3, the upward extension classes in Part 20 and the telecoms classes in Part 16 run on 56 days. Start work a day early against the wrong period and the development is not permitted development at all, which is the most avoidable enforcement problem in the Order.

The periods sit in the conditions attached to each class, not in a single table. That is why they get mixed up.

Why the periods differ by class

Each class in Schedule 2 of the General Permitted Development Order 2015 carries its own procedural condition, written when the class was introduced. Part 6 has run on 28 days since long before the change of use classes existed. The neighbour consultation scheme for larger home extensions was bolted on in 2013 with a 21-day representation period inside a 42-day determination window. The change of use classes that arrived from 2013 onwards were given 56 days, matching the eight weeks for a minor planning application.

Nobody has ever rationalised them. So the period is a property of the class, and the only safe method is to read the condition in the class you are relying on before you diary a date.

The second complication is what you are waiting for. In some classes the right is conditional on the authority notifying you that prior approval is not required, or granting it. In others the right crystallises on the expiry of the period without a determination. The practical effect is similar. The wording is not, and on a contested site the wording is what matters.

The 28 day classes

Part 6 covers agricultural and forestry development. For the larger agricultural buildings and for private ways, the developer applies to the authority for a determination as to whether prior approval of siting, design and external appearance is required. Development must not begin before the authority notifies that approval is not required, or grants approval, or 28 days have passed from receipt of the application without a notification.

Part 11 Class B covers demolition. Where the demolition requires prior approval of the method of demolition and any proposed restoration of the site, the authority has 28 days from receipt to notify its determination.

Those 28-day windows are short enough that a holiday period absorbs them. Submit on 20 December and the determination falls in the second week of January, when the registry is still catching up on validation, so there is a real risk of a notification arriving on day 30 after you have already started.

The 56 day classes

Fifty-six days is the modern default, and it covers most of what a landlord or investor will use.

Within Part 3, the prior approval matters differ sharply from class to class even though the period is the same. The commercial to residential route carries vacancy and continuous use requirements that catch people out, which is the subject of Class MA vacancy and continuous use conditions. The agricultural routes turn instead on proof of the previous lawful use, covered in proving the building was in agricultural use under Class Q.

What counts as the date of receipt

The period runs from the date the authority receives the application, and that date is a question of fact the authority records on its register. Three things stop the clock starting.

An application missing a required document does not start the period. Each prior approval class lists what accompanies the application: a written description, a plan indicating the site, the developer's contact address, and for several classes a floor plan, elevations or specified technical statements. Omit one and you have not made the application the class describes.

An incorrect fee does not start the period either. Prior approval applications carry fees set by the national fee regulations, and an underpayment leaves the application invalid until the balance is received. The date then becomes the date of the corrected payment, which can move a 56-day expiry by a fortnight.

Ownership certificates apply to prior approval applications in the same way they apply to planning applications, and a missing or wrong certificate is an invalidity. The ownership certificates A to D rules are worth checking where the building is leased or the access crosses third party land.

Deemed approval and how to rely on it

Where the period expires without a determination, and the class provides for it, you may proceed. Two cautions apply.

First, you must build exactly what you described. Deemed approval attaches to the submitted details, so a scheme altered between submission and construction is not covered and the whole right can fall away.

Second, you need evidence of the submission date and of the absence of a determination. Keep the portal receipt, the authority's acknowledgement, the register entry printed on the day the period expires, and a note of any telephone conversation. Then write to the authority stating that the period has expired, the date it expired, and your intention to proceed in accordance with the submitted details. That letter is not required by the Order. It is the document you will want if an enforcement officer arrives.

Where the authority has refused prior approval, there is an appeal to the Planning Inspectorate against the refusal. Where it has simply not determined, there is no non-determination appeal in the usual sense because the right is deemed instead, which changes the calculation that otherwise applies when weighing up appealing non-determination or waiting.

Recording the date of service

Build the file on the day you submit, not on the day you need it.

1. Submit online and save the submission receipt as a PDF with the date in the filename.
2. Email the planning registry a short note confirming what was submitted and asking for the date of receipt to be confirmed in writing.
3. Record the register reference as soon as it appears, and screenshot the validation date shown.
4. Diary the expiry date, and a reminder one week before it.
5. On the expiry date, screenshot the register again to show no decision was issued.
6. Write to the authority before work starts, setting out the dates and your intention to proceed.

An illustrative example. A prior approval application for a change of use to two flats is submitted on 4 February and acknowledged with a receipt date of 4 February. The 56 days expires on 31 March. On 12 February the authority emails asking for a floor plan that was not submitted. The clock never started, and the period now runs from the date the plan arrives. A developer who diarised 31 March from the original submission would have started a month early.

If you are weighing a prior approval route against a full application, enter the postcode on PlanScope to see which of the 66 report types the site's recorded constraints are likely to trigger either way.

This is general guidance, not legal advice. A Lawful Development Certificate is the only formal way to confirm that works or a use are lawful, so check the position with your local planning authority or a qualified professional before relying on a permitted development right. PlanScope provides AI-assisted draft reports for planning applications. Reports should be reviewed before submission. We do not guarantee planning approval.