Prior approval procedure and the deemed grant trap

The prior approval deemed grant is real, it is used, and it fails more often than it works. Paragraph W of Part 3 of Schedule 2 to the GPDO 2015 provides that development may begin where 56 days have passed from the date the local planning authority received the application without the authority notifying the applicant of its decision. The catch is in every word of that sentence, and the one that does the damage is "received".

Landlords converting under Class MA or Class Q should treat the 56 days as an opportunity to plan around, never as a safety net.

What paragraph W actually governs

Paragraph W is the procedure that sits behind most of the prior approval classes in Part 3. It tells you what to submit, who the authority must consult, what publicity is required, how long the authority has, and what happens if it says nothing.

It does not tell you what the authority may consider. That comes from the class itself. Class MA lists its matters, Class Q lists different ones, and the class can add information requirements on top of paragraph W. Read both together, in that order, every time.

The classes most relevant to a landlord are Class MA for commercial, business and service premises to dwellinghouses, Class Q for agricultural buildings to dwellings, and Class L for movement between a dwellinghouse and a small house in multiple occupation, which has no prior approval requirement at all.

What a valid application must contain

Paragraph W sets the minimum. A written description of the proposed development, including details of any building or other works. A plan indicating the site and showing the proposed development. The developer's contact address and email address. The fee.

Each of those is a point of failure, and the plan is the usual one. A plan "indicating the site" is a red line location plan. A plan "showing the proposed development" is a layout of what you intend to build or convert. Submitting only the first is the single most common reason a prior approval application goes nowhere.

Then the class requirements. Class MA, for example, requires the authority to consider transport impacts, contamination risk, flooding risk, the impact of noise from commercial premises on future residents, and the provision of adequate natural light in all habitable rooms, with an additional consideration where the building is in a conservation area. Each of those needs something in the submission addressing it.

Natural light is the one that catches conversions of deep plan units. A bedroom served only by a borrowed light or a rooflight over a 9 m deep plan will not satisfy it, and the authority is entitled to refuse on that ground alone.

Paragraph W also permits the authority to refuse the application where it considers the developer has provided insufficient information. That is a refusal, not an invalidation, and it carries a right of appeal.

The 56 days, and when they start

The period runs from the date the authority received the application. Not from the date it was validated, not from the date the case officer was assigned, and not from the date the fee cleared if the fee was paid with the application.

That makes the receipt evidence the most valuable document in the file:

• The submission acknowledgement from the Planning Portal or the authority's own system, with its timestamp.
• The payment confirmation, with the reference and the amount.
• A complete copy of exactly what was uploaded, file by file.
• Any email from the authority acknowledging receipt, which is worth asking for on day one.

Count the days precisely. Day 56 following the date of receipt is not the same as 56 days from the Monday you submitted, and an argument about one day is an argument you will lose without the paperwork.

Be careful with correspondence. A longer period can be agreed in writing between the applicant and the authority, and an agreement reached casually in an email thread can displace the 56 days entirely. Check the current text of paragraph W, and do not agree to an extension because a case officer asks politely while on leave.

The deemed grant, and what it actually permits

Here is the part most people misunderstand.

Where the 56 days expire without a decision, the development may begin, and paragraph W requires it to be carried out in accordance with the details provided in the application. Not in accordance with what you would have liked to build. In accordance with what you actually submitted.

So a thin application produces a thin right. If your layout plan showed a two bedroom flat with a particular window arrangement, that is what you may build. If the plan was ambiguous, your permission is ambiguous, and the ambiguity will be resolved against you by the next person who looks at it with a professional interest.

The deemed grant also produces no decision notice. There is no document to hand to a lender's solicitor. The remedy is a certificate of lawfulness for proposed use or development under section 192 of the Town and Country Planning Act 1990, or under section 191 once the work is done, which is the only formal way to establish that the development is lawful. Budget for it on any scheme you intend to refinance or sell.

Conditions that apply even on a deemed grant

The Order imposes its own conditions on each class, and those conditions survive a deemed grant untouched.

For Class MA that means the building must have been in a Class E use for at least two years before the application, it must have been vacant for at least three continuous months immediately before, and the floorspace changing use is capped. The class is unavailable for listed buildings and for certain designated land. None of that is waived because the authority missed a deadline. A deemed grant on an application that never satisfied the class conditions is worth nothing.

Class Q carries its own set, including limits on the extent of works and a requirement that the building was in agricultural use at the relevant date.

Where the trap closes

Three ways this goes wrong in practice.

The authority issues its decision on day 57 and asserts a later receipt date. Without your timestamped acknowledgement, you are arguing about a diary entry.

The class conditions were never met, usually the vacancy period or the two year Class E use. The deemed grant is then a right to do something the Order never permitted, and the works are unauthorised. Evidence the vacancy with utility records, council tax or business rates records and dated photographs before you apply.

The submitted details were inadequate, so what was permitted is unclear. This surfaces at sale, years later, and it is expensive to fix.

Where a conversion needs contamination or noise evidence, submitting a contaminated land assessment and a noise impact assessment with the application serves two purposes. It answers the class matters, and it fixes the technical basis on which a deemed grant would operate.

Appeal rights on refusal

Refusal of prior approval carries a right of appeal to the Planning Inspectorate under section 78, because it is a refusal of an approval required by a development order. The deadline is six months from the date of the decision notice for most cases, and written representations is the usual procedure.

The appeal is narrow. The inspector considers only the matters the class puts in issue, so an argument about the overall merits of the conversion will not assist. Where the refusal was for insufficient information, the appeal becomes a question of whether the information supplied was adequate for the matters listed, which is a more winnable point than people assume.

Managing the timetable

Submit with everything the class asks for, including the technical reports, rather than submitting light and hoping for the clock. Ask for written acknowledgement of receipt on the day. Diary day 40 and day 56. Chase at day 40 in writing, politely, and keep the reply.

If the authority has not determined by day 56, do not simply start. Write to the authority stating that the period has expired, setting out the receipt date and the details you consider to be permitted, and keep that letter. Then apply under section 192 if the asset matters.

The planning law timeline is where to follow amendments to Part 3, and the parallel case of a condition that arises by operation of law rather than by decision is covered in the piece on the deemed biodiversity gain condition.

This is general guidance, not legal advice; 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.

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