How prior approval works and what deemed consent means

Prior approval is not a planning application, and treating it as one is the source of most of the trouble it causes. The General Permitted Development Order 2015 has already granted permission for the development. What the prior approval procedure does is attach a condition to that grant, requiring the authority to consider a short, closed list of matters before work starts. Transport and highways. Contamination. Flooding. Noise. Whatever the particular class specifies, and nothing else.

That framing decides everything downstream, including what an officer may refuse on, what conditions may be imposed, and what happens when the determination period runs out.

What the authority may and may not consider

Each class that requires prior approval sets out its own list of approval matters. A change of use under Part 3 might list transport and highways impacts, contamination risks, flooding risks and the impact of noise from commercial premises on the intended occupiers. A telecommunications installation under Part 16 lists siting and appearance.

An officer who refuses because the elevation is unattractive, on a class that does not list design, has stepped outside the power. So has one who refuses on loss of employment floorspace where the class says nothing about it. This is worth stating plainly in the covering letter, politely, because it shapes the officer's report.

The flip side is that a scheme which does not qualify for the class at all gets nowhere. If the building is not within the description, or an exclusion applies, or the site sits in an area where an Article 4 direction has removed the right, there is no permission to condition. Prior approval cannot cure that.

The notification, the plans and the fee

A prior approval application is made in writing, with the information the relevant paragraph of the Order requires. For Part 3 that means a written description of the proposed development, a site plan with the site edged or otherwise identified, contact details and, where the class requires it, the specific assessments listed.

Drawings should be good enough to define what is being relied on. Vagueness works against you later, because a lawful development certificate or an enforcement argument will turn on exactly what was notified. Submit floor plans and elevations even where the Order does not demand them.

A fee is payable, and the fee regulations have been indexed annually since April 2025, so check the current schedule rather than a figure from a two year old note. The Planning Portal sets out what is due for each type of prior approval application.

Publicity and consultation

Where the Order requires it, the authority must publicise the application, usually by site notice or by notice served on adjoining owners and occupiers, and allow a period for representations. For Part 3 that period is 21 days.

Statutory consultees come into play where the class says so. A highway authority for an access. The Environment Agency where flood risk is a listed matter. The authority then has to take any representations into account when deciding whether prior approval is required and, if it is, whether to give it.

Determination periods and the deadline that matters

The periods differ by Part, and assuming they are all the same is a common error.

The clock runs from the date the authority receives the application, not from validation, and it is calendar days rather than working days. Check the wording of the Part you are relying on before you diarise anything, because the Order is the only authority on this.

Deemed consent and why relying on it is uncomfortable

Under the Part 3 procedure, development may begin once one of three things has happened: the authority notifies you that prior approval is not required, it notifies you that prior approval is given, or 56 days pass from receipt without the authority notifying you of its determination. That third limb is what people mean by deemed consent.

It is real, and it is used. But it clears one hurdle only.

Everything else in the class still binds. The floorspace limits, the exclusions, the date the building has to have been in the qualifying use, the conditions attached to the class, the requirement that the development be completed within the stated period. Deemed consent does not confirm that any of those are satisfied. It confirms that the authority ran out of time on the approval matters, and nothing more.

Two practical cautions. Keep proof of the date of receipt, because the whole argument rests on it, and a recorded delivery slip or an acknowledged email is worth more than a portal timestamp you cannot export. And take a lawful development certificate under section 192 before committing money, because a lender or a buyer will want something better than a letter that never arrived.

Conditions on a prior approval

Where prior approval is given, the authority may impose conditions reasonably related to the subject matter of that approval. A condition requiring a construction traffic management scheme on a class where transport is an approval matter is defensible. A condition about materials, on a class that does not list design, is not.

Conditions imposed on the class itself by the Order are different again. Those apply automatically and cannot be negotiated away. Part 3 classes typically require the development to be completed within a stated period from the date of approval, and missing it means the permission lapses.

Appeals, and when prior approval is the wrong route

A refusal of prior approval can be appealed to the Planning Inspectorate. The deadline depends on the type of application, so read the decision notice and check the current guidance rather than assuming six months. Appeals turn almost entirely on whether the refusal reason sat within the approval matters, which is why the scope argument is worth making early.

Sometimes the honest answer is that prior approval is the wrong vehicle. If the scheme needs design flexibility, or the building falls outside the class description, a full application with a proper Planning Statement is faster than two refused notifications and an appeal.

Most householder work never reaches this procedure at all. A porch under Class D, an outbuilding under Class E and fences and walls under Part 2 are permitted outright, subject to their own limits, with no notification required. Prior approval is the exception rather than the rule, and it applies where the Order decided that one or two specific impacts needed local scrutiny.

Enter your postcode on PlanScope to see which supporting documents a prior approval or full application at your site 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. A lawful development certificate is the only formal way to confirm that works are lawful, so check the position with your local planning authority or a qualified professional before relying on any permitted development right.