Prior approval applications and how the clock works

A prior approval application runs on a clock that starts when the council receives it, not when the council validates it. For most of the classes that use the procedure the period is 56 days, and if the authority has not notified you of its decision by the time that period expires, you may proceed. That deemed consent provision is the single most valuable feature of the route for a landlord or investor, and it is also the one authorities work hardest to avoid, usually by arguing that the application was never complete and so the clock never started.

Get the submission right on day one and the timetable works for you. Submit something thin and you will lose the argument about when the period began.

What prior approval decides

Prior approval is not a planning application, although it looks like one. The development is already permitted by the General Permitted Development Order. What the order does, for certain classes, is make that permission conditional on the authority first considering a defined list of matters.

That list is class-specific and it is a closed list. For a commercial to residential conversion the matters include transport and highways, contamination, flooding, noise from commercial premises, the provision of natural light to habitable rooms, and, in some circumstances, the effect of the loss of the existing use. For an agricultural building conversion the matters are different again. For telecommunications the matters are siting and appearance.

The consequence matters. An officer cannot refuse prior approval because they dislike the design, unless design is one of the specified matters for that class. Where a refusal strays outside the list, that is a strong appeal point.

When the clock starts, and what stops it starting

The period runs from the date the authority receives the application, and the order specifies what an application has to contain. Where an element is missing, the authority's position will be that no valid application was received.

Protect yourself with three habits. Submit by a route that gives you a dated receipt, and keep it. Include every item the class requires, checking the order itself rather than the council's web form. And write a short covering schedule listing each required item against the document that provides it, so that a later dispute is answered by one page.

Where the site straddles a boundary the position is more awkward still, because two authorities are each running their own clock. Applications made to two councils need the same care taken twice.

The 56 day rule and deemed consent

For the classes that use it, the condition is expressed as a prohibition on beginning development before one of three things happens. You receive written notice that prior approval is not required. You receive written notice granting prior approval. Or the 56 day period expires without the authority notifying you of its determination.

Two points are widely misunderstood.

First, deemed consent does not suspend the rest of the class. Every other limitation and condition in the class still applies, so a scheme that exceeds a floorspace cap or breaches a height limit is not lawful merely because the authority went silent. The deemed route gets you past the prior approval requirement and nothing else.

Second, the order does not provide for the kind of extension of time agreement used on planning applications. Authorities sometimes ask for one anyway. Agreeing is a commercial decision, and refusing is not obstructive.

Not every class uses 56 days. The larger home extension route under Part 1 operates a 42 day neighbour consultation period, and other classes have their own periods. Read the class.

The information the application must contain

The order sets out what must accompany the application, and for the busier classes the list has grown.

Where the class requires an assessment, supply a real one. A Flood Risk Assessment for a site in Flood Zone 2 or 3, and a Noise Impact Assessment where nearby commercial premises could affect the new residential units, are the two most commonly skimped. A paragraph asserting that flood risk is not an issue is not an assessment, and it hands the authority the argument that the application was incomplete.

Fees and the absence of validation

Prior approval fees are set by the national fees regulations and are generally lower than the equivalent full application. Check the current figure on the day you submit, because the schedule is indexed annually.

The important difference from a planning application is procedural rather than financial. There is no validation stage in the sense you are used to, with a checklist and a request for missing documents. Either the authority received an application containing what the order requires, or it did not. That is why the covering schedule matters so much, and why an incomplete submission is far more damaging here than on a full application, where the council simply asks for more.

Once determined, the decision goes on the public record like any other, and the statutory planning register will show it.

Refusal and the right of appeal

A refusal of prior approval is appealable to the Planning Inspectorate in the same way as a refusal of planning permission, and the appeal periods that apply to the relevant type of development apply here too.

Appeals on these cases are often narrow and winnable, because the question is confined. Did the authority address only the matters the class specifies. Did it apply the class limitations correctly. Did it refuse on a ground that is not within its remit.

The other appeal route people forget is non-determination. Where deemed consent has arisen you need no appeal at all. Where the authority has refused on an incorrect reading of the class, the written representations route is proportionate and relatively quick.

Conditions on a prior approval

Authorities can impose conditions, and the scope of that power is limited to the matters for which prior approval was required. A condition about contamination on a class where contamination is a specified matter is within scope. A condition about external materials on a class where appearance is not a specified matter is open to challenge.

Read the conditions on the notice against the class before you start work. Where a condition looks out of scope, raise it promptly, because building in breach of a condition attached to a prior approval leaves the development outside the permission the order gave you.

Where the scheme is marginal on one of the specified matters, a well-evidenced supporting statement does more work than any amount of correspondence. Even on a prior approval, a short Planning Statement that takes each specified matter in turn and answers it with evidence is what gets a decision inside the period.

This is general guidance, not legal advice, and a Lawful Development Certificate is the only formal way to confirm that works are lawful. 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.