Permitted development rights and the prior approval trap

A prior approval application is not an application for planning permission. It asks the local planning authority to determine whether its approval is required for a short, closed list of matters, and if the authority fails to notify a determination within the period the Order specifies, the development may usually proceed as though approval had been given. That deemed consent is the reason prior approval classes are attractive, and the reason they go wrong. Deemed consent runs from a valid application, and an application missing a document the Order requires is not valid.

So the question that decides most of these cases is not whether the design is acceptable. It is whether the paperwork was complete on the day it was submitted.

Which classes require prior approval and why

Permitted development is not one regime. Schedule 2 to the General Permitted Development Order 2015 contains parts covering householder development, changes of use, agriculture, telecommunications, renewables and new dwellings above or in place of existing buildings, and the procedure differs between them.

• Part 1 Class A: larger rear extensions to houses, through the neighbour consultation scheme.
• Part 3: changes of use, including Class MA commercial to residential, Class Q agricultural building to dwellinghouse, and Class R agricultural to flexible commercial use.
• Part 6: agricultural development on units of five hectares or more, where the works fall within the category the Order reserves for scrutiny.
• Part 16: electronic communications apparatus.
• Part 20: upward extensions and demolition and rebuild to create new dwellings.

The logic is the same throughout. Parliament has granted the right in principle and reserved a handful of impacts for local scrutiny. The authority cannot refuse on grounds outside that list, and it cannot treat the submission as a full application.

The information the authority must be given

Each class sets out what accompanies the application, and the requirements are specific. A written description of the proposed development. A plan showing the site. The developer's contact address and email. The fee. And for classes with prior approval matters, the evidence on each of those matters.

Where a class requires a report, the report is part of the validity test rather than a nice extra. Class MA, for example, requires prior approval on transport impacts, contamination risks, flooding risks, noise from commercial premises, the provision of adequate natural light in all habitable rooms, and in a conservation area the impact of the loss of the ground floor commercial use. A submission with nothing on natural light is incomplete, and the deemed consent period does not start.

Three habits protect the clock.

1. Submit a cover letter listing each item the Order requires and the document that satisfies it, by page number.
2. Ask the authority to confirm the date it treats the application as valid, in writing, and keep the reply.
3. Diarise the expiry date from that confirmed date rather than from the date you pressed send.

Determination periods and deemed consent

The periods differ by class, so read the class rather than working from memory.

Deemed consent is not a licence to build whatever was drawn. The development must be carried out in accordance with the details submitted, and every condition the Order itself imposes still applies. That is the second trap, and it is a bigger one than the first.

Conditions imposed by the Order itself

Order conditions bite whether or not the authority ever writes to you. They are not conditions on a permission, so there is no decision notice listing them, and nobody sends a reminder.

Typical examples include a requirement that materials be of a similar appearance to the existing building, a limit on the period within which the development must be completed, a restriction on further extensions, a requirement that the use begin within a stated period, and a prohibition on works outside the approved details. Class Q carries conditions about the extent of building operations reasonably necessary for the conversion. Part 20 classes carry conditions on construction hours and on the provision of a construction management plan.

Read the class in full, print it, and keep it with the decision or the acknowledgement. When the house is sold, the purchaser's solicitor will ask how the works were authorised, and the answer is the class, the application, the determination or the expiry date, and compliance with the conditions in the Order.

The neighbour consultation scheme in practice

For larger rear extensions to houses, the authority notifies the adjoining owners and occupiers, describes the development and gives them 21 days to object. If nobody objects, the authority cannot consider amenity and the development proceeds. If someone objects, the authority considers the impact on the amenity of adjoining premises only, which means overlooking, loss of light and loss of outlook on those specific properties.

Two points people get wrong. Adjoining means sharing a boundary, so an objection from a house across the road does not engage the scheme. And the authority is considering amenity, not design, so objections about materials or character carry no weight under this class.

If you expect objections, consider whether a householder planning application is the better route. A refusal under the scheme leaves you applying anyway, several weeks later, with a neighbour already mobilised.

What happens when prior approval is refused

There is a right of appeal to the Planning Inspectorate, on the same timescales as an appeal against refusal of planning permission, and a householder appeal route where applicable. The appeal is confined to the prior approval matters, which makes it a narrower and often quicker argument than a full planning appeal.

Before appealing, check the refusal against the class. Authorities sometimes refuse on grounds outside the reserved matters, which is a straightforward appeal point. They also sometimes refuse for want of information they never requested, which is a different and weaker position for them.

Where the refusal is on substance, resubmitting with better evidence on the single matter in question is usually faster than an appeal. Where the scheme needs more than the class allows, a full application with a supporting Planning Statement gives you room to argue the merits that prior approval excludes. To see which supporting documents that route needs, browse the report types.

Recording compliance for a future sale

Keep a single file: the application, the plans as submitted, the acknowledgement with its validity date, the determination notice or evidence of expiry, photographs during construction, and a note of the Order conditions with evidence of compliance against each.

Where any doubt remains, apply for a Lawful Development Certificate. A certificate under section 192 confirms that a proposed use or operation would be lawful, and one under section 191 confirms an existing one is. It is the only formal way to establish that works are lawful, and it removes the argument from a future conveyance entirely. Buyers' solicitors accept a certificate. They do not always accept a bundle of correspondence.

Time limits matter here too, and the enforcement position has moved, which is set out in the note on enforcement time limits moving to ten years. Changes to the Order itself are frequent, so follow them through the planning law timeline rather than relying on a printed copy.

This is general guidance, not legal advice. 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.