The High Court has resolved an awkward question about the GPDO prior-approval timetable: if a council makes and notifies a decision within the statutory period, but that decision is later quashed by the court, does the applicant retrospectively acquire deemed consent because there is now no valid decision?
In R (Di Mambro) v East Devon District Council [2026] EWHC 1961 (Admin), HHJ Russen KC said no. A timely notification is not converted into a failure to notify merely because the underlying decision is later quashed.
The Di Mambro prior approval ruling arose under Class R, but the reasoning is important for other Part 3 prior-approval rights that use the same paragraph W procedure.
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The Class R proposal
The case concerned an agricultural building at Shoots Lane, Sheldon in Devon. An application was made on 5 March 2025 under Class R of Part 3 of Schedule 2 to the GPDO for a change from agricultural use to a flexible commercial use, described in the case material as a guesthouse.
Class R allows qualifying agricultural buildings and land within their curtilage to change to specified flexible commercial uses. Since the 2024 amendments those uses include Use Class C1 hotels, alongside Class B2, B8, E and certain other rural diversification uses.
The right is not automatic simply because an application is labelled ‘Class R’. The building and proposal must first satisfy the Class R headline or definitional requirements, as well as the relevant limitations and conditions.
There are also two procedural routes within Class R. Where the cumulative Class R floorspace on the established agricultural unit does not exceed 150 square metres, the developer gives notice to the council. Where it exceeds 150 square metres, an application is required to determine whether prior approval is needed and paragraph W applies. Di Mambro concerned that second route, with its 56-day timetable.
What did East Devon decide?
East Devon District Council gave notice of prior approval on 29 April 2025. That was within the 56-day period in paragraph W.
Following a legal challenge, the Council accepted that its officer report had not properly addressed key threshold questions, including whether the building was an agricultural building for the purposes of the right and whether the proposal fell within Class R.
A consent order was therefore made which quashed the prior-approval decision and remitted the application to the Council for redetermination. The claimant then pursued additional remedies, arguing in substance that once the original decision had been quashed, the 56-day period had already expired without a valid decision and the deemed-consent route should therefore apply.
How paragraph W(11) works
Paragraph W is the common prior-approval procedure used by a number of change-of-use rights in Part 3 of the GPDO. Paragraph W(11) prevents development from beginning until one of three things has happened:
- the authority notifies the applicant that prior approval is not required
- the authority gives prior approval
- 56 days expire without the authority notifying the applicant whether prior approval is given or refused
The third route is often described as deemed consent. Its purpose is to stop a prior-approval application being left in limbo simply because the authority does nothing within the statutory period.
The crucial distinction in Di Mambro is that East Devon did not do nothing. It made and notified its decision within 56 days.
Why did the deemed-consent argument fail?
The Court treated paragraph W(11)(a), (b) and (c) as genuine alternatives. Once the authority had notified a decision in time, the case had fallen within the timely-decision route. The later quashing of that decision did not retrospectively transform what happened into 56 days of silence.
HHJ Russen KC rejected the idea that quashing the decision should ‘airbrush’ the fact of timely notification from legal history. The Court drew on wider public-law authority showing that an unlawful administrative act is not necessarily treated as though it never existed for every legal purpose simply because it is later quashed.
That matters because the claimant’s interpretation would produce a rather odd result: successfully challenging a flawed but timely prior-approval decision could hand the applicant the very permission route that the challenge was intended to undo.
The Court also distinguished cases such as R (Nunn) v First Secretary of State [2005] EWCA Civ 101, where the problem was a failure to notify within the statutory time. Di Mambro was different because the authority had acted within time.
What happened to the 56-day clock after quashing?
The consent order expressly remitted the application to East Devon for redetermination. On the terms of that order, the Court held that the paragraph W timetable was re-engaged and the Council had a further 56 days from remittal to make and notify a fresh decision, subject to any agreed extension of time.
That point should be handled with some care in other cases. The judgment does not mean that every quashing order in every prior-approval regime automatically produces an identical fresh timetable regardless of its wording. Here, remittal for redetermination was an express part of the order and paragraph W governed the application being redetermined.
The Class R headline requirements still matter
There was a second practical reason why the claimant’s concern did not justify further relief. If the building did not satisfy the basic Class R requirements in the first place, the permitted development right could not lawfully be relied upon anyway.
Prior approval is not a magic cure for a proposal that falls outside the permitted development class. The correct order of analysis is always:
- does the development fall within the description of permitted development?
- are any limitations or exclusions triggered?
- what conditions apply?
- does the prior-approval procedure need to be followed, and was it followed correctly?
Our main Class R guide sets out the current right for agricultural buildings to flexible commercial use.
Why the Di Mambro prior approval ruling matters in practice
For applicants, the decision removes a potentially dangerous assumption. If the council made a decision within the 56 days, a later quashing does not mean you can immediately start work on the basis that the original statutory period has expired.
For objectors and councils, it avoids a perverse consequence of judicial review. A successful challenge to a defective prior-approval decision can lead to a fresh lawful decision rather than automatically handing the developer the benefit of the no-decision route.
For advisers, keep the two situations separate:
- no notification within the statutory period can engage paragraph W(11)(c)
- a timely notification which is later quashed does not retrospectively become a no-notification case
The point is most directly relevant to the Part 3 classes that use paragraph W. It may also be informative when considering other deemed-consent mechanisms, but different GPDO classes use different wording and timetables, so the result should not be transplanted mechanically into another regime.
More generally, this is another reminder that permitted development is still a statutory planning permission. The exact words of the relevant class and procedure matter.
Primary and open-access sources
Created: 23rd August 2026 | Di Mambro prior approval
