Amending what a prior approval granted

Changing a scheme that was approved through the prior approval procedure is harder than changing one that holds a planning permission, and the reason is structural. Your permission did not come from the council. It came from the General Permitted Development Order 2015, and what the council issued was a determination on a short list of prescribed matters. The tools that let you tweak a planning permission, sections 96A and 73 of the Town and Country Planning Act 1990, are aimed at permissions granted by the authority, so their application to a prior approval is doubtful and practice varies between councils.

In most cases the clean answer is a fresh prior approval application for the revised scheme, provided the revision still sits inside the class. Work out that second point first, because everything else follows from it.

Why prior approvals resist amendment

Under section 59 of the 1990 Act, a development order can itself grant planning permission. The GPDO does that for the classes in Schedule 2, subject to limitations and conditions. Where a class requires prior approval, the condition on the grant is that you apply to the authority and it determines whether its approval is required for specified matters, such as transport and highways impacts, contamination risk, flooding risk, noise or the design and external appearance.

So the decision notice you hold is a determination about those matters. It is not the source of the permission. That distinction sounds academic until you ask a council to make a non-material amendment to it and are told, correctly in most officers' view, that there is no permission of theirs to amend.

Two consequences follow. The first is that the scope of what the council ever considered is narrow, so a change to something outside that scope may not need their agreement at all. The second is that a change to something the class itself controls, such as a floorspace limit or an external alteration the class does not permit, is fatal to reliance on the right, whatever the council says.

Whether the revised scheme is still inside the class

This is the analysis that decides your route, and it has to be done against the wording of the class rather than against the decision notice.

Read the class in three passes. First the limitations, which are the tests the development must satisfy to be permitted at all. Then the conditions, which are the obligations attached to the right, including the requirement to apply for prior approval. Then article 3 and the general restrictions in article 2(3), Article 4 directions and any condition on an earlier permission that removed the right for that land.

Where the revision keeps the scheme within every limitation, you are looking at a fresh prior approval. Where it breaches one, the right disappears entirely and a full planning application is the only route. There is no middle ground, and there is no discretion in the authority to overlook a breach of a limitation. Our walkthrough of how the prior approval procedure actually works sets out the determination steps in order.

Submitting a fresh prior approval

A second application costs another fee and another determination period, but it produces a document that means something.

1. Prepare the application against the current wording of the class, not the wording that applied when you first applied. Classes are amended often, and the version in force on the date of your new application is the one that governs it.
2. Check for anything that has changed on the ground since the first approval: a new Article 4 direction, a new conservation area boundary, a new listing, a change in flood zone mapping, a nearby permission that alters the highway position.
3. Submit the plans and information the class requires. Keep to that list. Extra material invites the authority to consider matters it has no power to refuse on, and to condition them.
4. Diarise the determination period, which is 56 days for most Part 3 classes and shorter for some Part 1 rights. Where the class provides for deemed approval on expiry, the date the period ends is a legal fact worth recording carefully.
5. Keep the earlier approval alive if you can. Where the earlier scheme was implemented or could still be implemented within its time limit, you retain the fallback while the new application runs.

That last point is the one people forget. Two approvals can sit side by side, and the earlier one is often the better negotiating position.

Where non-material amendment does and does not help

Section 96A allows an authority in England to make a non-material change to a planning permission relating to land in its area. The prevailing view among local planning authorities is that it does not reach a prior approval, because the permission came from the Order rather than from them. Some councils will nonetheless accept an application, or process an informal minor amendment request, and issue something in writing.

Treat any such document with care. It may be useful evidence that the council does not object, and that has practical value if enforcement is ever raised. It is not the same as a determination that your revised scheme benefits from the right, and a purchaser's solicitor will spot the difference.

Section 73 has the same problem, with an added one. A section 73 application varies a condition on a permission, and the conditions that matter to a permitted development scheme are usually conditions in the Order itself, which no local authority can vary. Where the council imposed its own conditions when granting prior approval, as Part 3 allows it to do, the position is less clear and it is worth asking the authority directly what route it will accept.

Ask in writing, and keep the reply. Officers move on, and so do policy positions.

Changes that take a scheme outside the class altogether

Some revisions look modest and are not. The recurring ones:

• exceeding a floorspace cap in the class, whether by adding units, enlarging the building or including floorspace that was previously discounted
• external alterations where the class permits a change of use only, which includes new windows, altered fenestration, new doors, plant, flues and external staircases
• increasing the number of dwellings beyond a limit in the class
• works beyond those reasonably necessary for the conversion, which is the test that most often defeats an agricultural conversion, as our note on the structural works test in a Class Q barn conversion explains
• height or projection changes that breach a dimensional limit, the frequent problem with upward extensions under Class AA
• a change in the building's use or vacancy history that breaks a qualifying condition

Where a revision does any of this, the choice is between reverting to something that fits the class or applying for planning permission for the whole scheme. A full permission is slower and carries policy risk, but it then gives you access to sections 73 and 96A for future changes, which is worth something on a scheme that will evolve.

Evidence of the approved position

Build a pack and keep it with the title deeds. It should hold the application form and reference, every drawing and document submitted, the decision notice or the evidence that the determination period expired without a decision, the date the development began and photographic evidence of it, and any correspondence with the council about the scope of the approval.

Prior approval rights are usually subject to a time limit for commencement, commonly three years from the date of approval, and an unimplemented approval simply expires. Record the commencement date and what was done to achieve it, because a purchaser or a lender will ask.

Where you are also assembling planning policy material for a parallel full application, a planning statement is the document that ties the fallback position to the policy case.

Drafting the first application to keep room to move

Prevention beats cure here. When you make the original prior approval application, describe the development in the terms the class uses and no more tightly. Submit the drawings the class and the council's local list require, and resist volunteering internal layouts, specifications or details that the authority has no power to assess, because anything submitted can end up listed on the decision notice as an approved plan.

Where the authority proposes a condition, ask what power it is imposed under and whether it is necessary to the matters the class allows it to consider. Conditions on prior approvals are more constrained than conditions on a planning permission, and an unnecessary one narrows your room later.

This is general guidance, not legal advice. Check the position with your local planning authority or a qualified professional before relying on it, and remember that a Lawful Development Certificate is the only formal way to confirm that works are lawful. To see what a site and its constraints are likely to require before you apply, enter your postcode on PlanScope.

PlanScope provides AI-assisted draft reports for planning applications. Reports should be reviewed before submission. We do not guarantee planning approval.