Prior approval determination periods and deemed consent

If a local planning authority does not notify you of its decision on a prior approval application within the period set by the General Permitted Development Order, you can usually start the development anyway. That is the single most useful thing to know about the prior approval determination period, and the single most dangerous, because it only works if your application was valid on the day it was received and you comply with every condition in the Class.

Agents rely on it more often than they admit. It is worth knowing the mechanics precisely before you advise a client to put a digger on site.

Which classes carry a prior approval procedure

Prior approval is not one procedure. Several Parts of Schedule 2 to the Order have their own, with different periods, different triggers and different things the authority is allowed to consider.

The ones most often met in practice are the larger home extension procedure in Part 1, the change of use classes in Part 3 which share the procedure in paragraph W, agricultural development in Part 6, demolition in Part 11, telecommunications in Part 16 and the upward extension and redevelopment classes in Part 20.

Read the procedure attached to your Class rather than assuming paragraph W applies. Part 3 uses paragraph W and sets out the consultation requirements, the publicity, the matters the authority may consider and the 56 day period. Part 6 works differently: you first apply for a determination as to whether prior approval is required at all, and only if the authority says it is do you then apply for the approval itself.

The periods that apply to each

Part 20 classes have their own periods, which differ from the figures above and have been amended, so check the current text of the Order for upward extensions and for demolition and rebuild. The same caution applies to the solar and electric vehicle charging classes in Part 14.

Count the days properly. The period runs from the day after the authority receives a valid application, and it runs in calendar days including weekends and bank holidays. A 56 day period starting on a Monday in the middle of December ends in February, and nobody in the planning office will remind you.

What counts as the start of the period

Validity is where the arguments happen. The clock starts on receipt of a valid application, which means the correct form, the correct fee, the plans and information the Class requires, and anything else the procedure specifies.

If the authority writes a fortnight in to say the submission was incomplete, your position is weak unless you can show the application contained everything the Order requires. Note that the authority cannot impose its own local list requirements on a prior approval application: the information required is whatever the Class specifies, not whatever the validation checklist says.

Three habits remove most of the risk. Submit through the national portal so the receipt date is recorded. Attach a covering schedule listing each item the Class requires against the document that provides it. And ask the authority to confirm the validation date in writing within the first week.

Where a change of use also needs a supporting statement, our note on Class MA vacancy and continuous use conditions shows the evidence those applications turn on.

Deemed consent where no decision is issued

Paragraph W provides that development may begin where the authority gives notice of approval, where it notifies the applicant that prior approval is not required, or where the period expires without the authority notifying the applicant of its determination.

That third limb is what people call deemed consent, although the Order does not use the phrase. The development is permitted by the Class itself, subject to the conditions in the Class, rather than by anything the authority has granted.

Two consequences follow. The conditions in the Class still bind you, including any requirement to complete within a stated period and any restriction on materials or design. And there is no decision notice, which means no document to show a funder, a buyer or a building control body.

That absence is the practical problem. A Lawful Development Certificate under section 192 of the Town and Country Planning Act 1990 is the only formal way to confirm that the development is lawful, and on a transaction it is usually worth the fee.

Risks of relying on deemed consent

The failure mode is almost always validity. An application that was short of a required plan, or where the fee was paid late, never started the clock, so the period never expired and the development is unauthorised.

The second risk is the condition you did not read. Several classes impose conditions that bite after the event, such as completion deadlines, requirements about external materials matching the existing building, or restrictions on subsequent use. Breaching one of those puts you outside the Class entirely, and the whole development becomes unauthorised rather than just the breach.

Third, Article 4 directions. A direction removing the Class takes the right away, and the prior approval procedure does not apply to a Class that no longer exists in your area. Check the direction register by address, not by ward.

Our notes on Class Q and proving the building was in agricultural use and on the works that are reasonably necessary under Class Q both deal with conditions of this kind, where the right depends on facts the authority may test later.

Extensions of time and whether they are available

Paragraph W allows the 56 day period to be extended where a longer period is agreed in writing between the applicant and the authority. That is a genuine agreement, not a unilateral notice from the council, and you do not have to give it.

There are good reasons to agree one. A statutory consultee response outstanding at day 50, a design change you want to make, or a committee date that falls just after the deadline. An approval is worth more than a deemed consent, because it comes with a notice.

There are also good reasons to refuse. If the authority has been unresponsive and the application is sound, letting the period expire gives you the development. Make that choice deliberately, with the client, and record the advice.

An illustrative example

Take an illustrative case: a Part 3 change of use application validated on 3 February. The 56 day period expires on 31 March. On 24 March the authority emails asking for a 28 day extension because the highway officer has not replied. The applicant declines, the period expires with no decision issued, and the development proceeds under the Class. Six months later a funder asks for evidence, and a section 192 certificate is obtained confirming lawfulness. This example is illustrative.

Appealing a refusal of prior approval

A refusal of prior approval is appealable to the Planning Inspectorate under section 78 of the 1990 Act. The deadline depends on the type of application: householder development uses the shorter householder appeals route, and other refusals use the general deadline, so check the current Planning Inspectorate guidance before relying on either.

The appeal is narrow in a helpful way. The inspector considers only the matters the Class allows the authority to consider, so an appeal statement that identifies a reason for refusal falling outside those matters is often the strongest point available. Officers do sometimes refuse on grounds drawn from the local plan rather than from the Class.

Write the statement around the closed list. A Planning Statement structured as a short answer to each permitted consideration, with the evidence attached, works better than a policy narrative.

And deal with the deemed consent question head on if it arises, because an inspector will want to know whether the application was valid and when the period expired.

Enter your postcode on PlanScope to see which reports a prior approval application is likely to need.

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