The 56 day prior approval deadline and deemed consent

Under Part 3 of the general permitted development order, a local planning authority has 56 days from the date it receives a valid prior approval application to tell you whether prior approval is given or refused. If it does not, you may begin the development in accordance with the details you submitted. That is the 56 day prior approval deemed consent mechanism, and it is a genuine right rather than a loophole.

It is also the part of permitted development most often misunderstood by the people relying on it. Deemed consent attaches to a valid application and to the particulars in it. A vague submission produces a vague right, and a submission the authority never treated as valid produces nothing at all.

Where the period comes from and how it is counted

The procedure is set out in the paragraph at the end of Part 3 that governs applications for prior approval across the classes in that Part. The period is 56 days beginning with the date on which the application was received by the authority.

Beginning with matters. The day of receipt counts as day one, which shifts the expiry date by one compared with the way most people count. Work it out on a calendar and write it down.

Other Parts use different periods. Householder larger extensions under Part 1 run to 42 days. Demolition under Part 11 runs to 28 days. Several agricultural classes in Part 6 use 28 days. The mechanism is the same in each case, and the number is not, so check the Part you are relying on rather than assuming 56.

The period can be extended by written agreement between the applicant and the authority. It cannot be extended unilaterally by the council, and a letter saying the application will be determined later is not an agreement.

What a valid submission needs

The clock starts on receipt of a valid application, so validity is the whole game.

The procedural paragraph requires a written description of the proposed development, a plan indicating the site and showing the proposed development, the developer's contact address, an email address if the developer is content to receive communications electronically, and the fee. Each class then adds its own documents: a flood risk assessment, a contamination assessment, a noise assessment, a transport statement, floor plans showing dimensions and the position of windows, depending on which prior approval matters apply.

Submit everything the class requires, even where you think a matter is obviously not engaged. A missing document is the standard reason for an authority to treat a submission as invalid, and an invalid submission means the 56 days never started.

Keep the evidence of receipt. The portal submission receipt, the payment confirmation, and the council's acknowledgement with the date on it. If you later need to rely on expiry, those three documents are your case.

Where a class is being used for commercial floorspace, the class-specific limits matter as much as the procedure, as with the rules covered in extending a shop under Part 7.

What the authority must do to stop the clock

The authority stops the clock by notifying you of its determination within the period. Making the decision internally is not enough. The notification has to reach you.

That distinction has real consequences. A decision signed on day 55 and posted on day 57 does not stop the clock. Nor does a decision recorded on the council's website without being sent, although arguing that point after you have seen it online is an uncomfortable position.

The authority must also carry out the publicity the paragraph requires, which is normally a site notice displayed for a period, or notice served on adjoining occupiers, with a period for representations. A failure to publicise does not extend the period, though it can create a different sort of argument later.

Three outcomes end the period. A notice that prior approval is not required. A grant of prior approval, with or without conditions. Or expiry without notification, which gives deemed consent.

Deemed consent and what it carries

Deemed consent is not a blank permission. It permits the development described in the application, carried out in accordance with the details submitted.

Every condition in the relevant class still applies. That includes completion deadlines, which several Part 3 classes impose, requiring the development to be completed within a stated number of years of the date of prior approval or of the expiry of the period. It includes the space standard condition for new dwellings created under permitted development. And it includes any class-specific requirement about the use of the building before and after.

So the practical instruction is to write the application as though it will become the consent, because it may. Describe the works and the resulting use precisely. Include the drawings you intend to build from, numbered and dated. If the submitted floor plans show a two bedroom flat and you build a three bedroom one, the deemed consent does not cover it.

Where the development involves an existing commercial building, the physical limits of the class still bind, as they do in the rules for extending an industrial building or warehouse under Part 7 Class H.

Whether to sign an extension agreement

Councils ask for extensions, usually because a consultee is late or an officer has gone on leave.

There is a reasonable case for agreeing. An express approval is cleaner than a deemed one, easier to explain to a buyer, and usually comes with conditions you can see rather than uncertainty you cannot. An authority that was going to refuse will refuse anyway, and a refusal you can appeal is better than a deemed consent you have to defend.

There is also a reasonable case for refusing, particularly where you believe the authority has no proper basis for refusal and is looking for time to find one.

If you agree, agree to a specific date in writing, not to an open-ended extension, and confirm it by email so there is a record. And diary the new date the same way you diaried the first.

Evidencing deemed consent for a lender

Deemed consent is the position that causes the most trouble on a sale or a refinance, because there is no certificate to produce.

Assemble a pack while the facts are fresh:

1. The full application as submitted, with every document and drawing, in the version that was sent.
2. The submission receipt and the fee payment confirmation.
3. The council's acknowledgement or validation letter showing the date of receipt.
4. A calculation of the 56 day expiry date.
5. Any correspondence with the authority during the period, including a note of any telephone call.
6. Photographs of the site notice in position, dated, if one was displayed.

Then consider applying for a lawful development certificate. It is the only formal way to confirm that works or a use are lawful, the application is decided on fact and law rather than on planning merits, and it produces a document a lender's solicitor will accept without argument. On a scheme of any value that fee is trivially small against the cost of a delayed completion.

A short Planning Statement setting out the chronology, the class relied on and the reason the development is lawful is the natural supporting document for that certificate.

Building out on a deemed approval

Build what you described, and keep proving that you did.

Take dated photographs at each stage, keep the as-built drawings with the submitted drawings, and record any change however minor. Where a change becomes necessary, the honest route is a fresh prior approval application or a planning application rather than a hope that nobody measures.

One last point on timing. Several classes impose a deadline for completing the development, and the clock on that runs from the prior approval date or the expiry of the period, not from when you get around to starting. A conversion that stalls for three years can find the right has lapsed underneath it.

Enter your postcode on PlanScope to see which documents a prior approval submission is likely to need.

This is general guidance, not legal advice. Check the position with your local planning authority or a qualified professional before relying on it. PlanScope provides AI-assisted draft reports for planning applications. Reports should be reviewed before submission. We do not guarantee planning approval.