Prior approval: How it actually works
HOMEOWNER GUIDE
If you’re extending your home without full planning permission, prior approval is the step most people underestimate — here’s how it really works.
The numbers, before you start. Most prior-approval applications succeed — but about one in five is refused, and which side of that line you land on depends heavily on what you are building. The first chart is the national picture; the second is our own analysis of how different homeowner projects actually fare.
One more figure from that sample: the median decision took 43 days, but almost a third (32%) ran past the 56-day mark — a reminder not to bank on the clock, which we come back to below.
If you are adding a big rear extension, converting the loft or putting up an outbuilding, you may be told that prior approval is a ‘formality’ — that because permitted development already grants the principle, the council’s sign-off is all but automatic. It isn’t, and treating it that way is what turns a quick route into a refusal, an appeal, or a build that runs months late and thousands over budget.
Used well, prior approval is genuinely useful: for the right project it is faster, cheaper and more certain than a full planning application — which is why larger home extensions alone make up more than half of all prior-approval applications in England. But it carries its own rules: fixed clocks, a narrow list of things the council can actually consider, and a few traps that catch homeowners who assume the hard part is over once permitted development applies. Here is how it works, in the order that matters to your project.
Not permission — and not plain permitted development
Planning control in England runs on three tiers. At one end, permitted development is development the GPDO 2015 grants automatically — no application, build by right. At the other, full planning permission means you apply and the council weighs the whole proposal against its development plan. Prior approval is the middle tier: the Order grants the right, but attaches a condition that before you start you must obtain the council’s approval of certain specified matters.
That distinction has teeth. A prior approval decision only binds the matters the legislation lists for that class — it is not a general planning permission, and it is not a lawful development certificate, which merely confirms that something is already lawful. Permission to develop comes from TCPA 1990, ss. 57–58; prior approval is a gate within a permitted development right, not a substitute for permission in the round. If you want the wider picture of what permitted development does and does not cover, start with our guide to permitted development and its limits.
The three answers the council can give
When you apply, the procedure in GPDO 2015, Sch. 2, para. W (and the equivalents in other Parts) leads to one of three outcomes. First, the council can decide that prior approval is not required — it is content the listed matters do not need its sign-off, and you proceed under the right. Second, it can decide approval is required and grant it, often with conditions you then have to meet. Third, it can refuse, in which case you cannot proceed under the right.
A refusal is not the end of the road: you have a right of appeal to the Planning Inspectorate under TCPA 1990, s. 78, you can submit a stronger application, or you can apply for full permission instead. One subtlety worth holding onto: “prior approval not required” lets you build just as effectively as a grant, but it is a narrower statement — it does not mean you never needed to apply. You did. The application is the thing that switches the right on.
The clock and the deemed-consent trap
Time limits come from GPDO 2015, art. 7. The council must decide within (a) the period the relevant class specifies, (b) eight weeks where none is specified, or (c) a longer period agreed in writing. In practice that means 42 days for a larger home extension under Part 1, and 56 days for most changes of use under Part 3, para. W(11) — Class Q, Class MA and the rest.
Here is the part people misread. For those rights, if the council does not notify you of its decision within the period, you have deemed consent and may proceed in line with your application. The operative word is notify: what matters is the council getting its decision to you in time, not when it was signed off internally. So diarise the exact expiry date and keep proof of what landed in your inbox and when — but never treat ordinary council delay as automatic permission until you have checked.
Two cautions. First, Part 20 upward extensions that create new flats are the big exception: they carry an eight-week period but no deemed consent, so silence grants nothing. Second, the clock can be extended — but only by written agreement under article 7(c). The Court of Appeal settled that point in Gluck (2020), ending earlier doubt about whether an extension was lawful at all. Until you sign up to one, the original deadline keeps running.
What the council can actually assess
The council cannot range across your whole scheme the way it can on a full application — it may only consider the matters the class puts in scope. For a larger home extension, Sch. 2 Pt 1 Class A.4 limits that to one thing: the impact on the amenity of adjoining premises, tested through the neighbour consultation scheme. Design and appearance are not for the council to judge here, which is why a refusal dressed up as “poor design” on a larger extension is usually outside its remit.
A Class Q barn conversion is the opposite: the checklist runs to transport and highways, contamination, flooding, noise, whether the building is structurally capable of conversion, design and external appearance, and the provision of natural light. The structural-capability test is where most schemes come unstuck. This is exactly where the “formality” myth bites — people assume the principle is settled, so the detail is a rubber stamp, when the detail is precisely what the council exists to scrutinise. Our guides to barn conversions and Class Q and to change of use and the Use Classes Order go deeper on those tests.
The same assumption catches homeowners. On a larger rear extension the principle is rarely the problem — what trips people up is treating the 42-day window as a rubber stamp, or breaking ground before the council has confirmed the right applies. Prove your case first, and the process does what it is meant to: it gets you building, fast.
The fees — and the commencement trap
Prior approval is cheap next to a full application, but the figures changed in April 2026, and many council pages still quote old numbers. The current statutory fees for England are below.
What a prior approval application costs
| Application type | Fee | Notes |
|---|---|---|
| Most prior approvalsLarger extensions, additional storeys, agricultural & forestry, demolition, solar | £249 | The standard rate for the great majority of rights. |
| Change of use with building operationse.g. Class Q, M, N where works are involved | £536 | £249 where the change involves no building works. |
| Class MAUse Class E to homes | £260 | Per dwellinghouse created. |
| TelecomsPart 16, Class A | £610 | Electronic communications code operators. |
Now the trap that costs the most. A permitted development right does not authorise development any part of which began before the prior approval application was made. You cannot start work and then regularise it — starting early can destroy the right entirely, leaving you needing full permission for something you could have done lawfully. And for changes of use under Part 3, the development must be completed within three years of the prior approval date. If enforcement is already on your mind, our guide to what happens if you build without planning permission sets out the real consequences.
When the rights don’t apply at all
Before you rely on any of this, check that the right exists where your property sits. Many permitted development rights — and the increased limits that go with them — fall away on article 2(3) land: conservation areas, National Landscapes (AONBs), National Parks, the Broads and World Heritage Sites, as well as on Sites of Special Scientific Interest.
An Article 4 Direction can go further and remove a right outright across a defined area — common in conservation areas and parts of London. Where a right has been withdrawn, prior approval is irrelevant; you need full permission. And keep the “original dwellinghouse” point in mind: allowances are measured against the house as it stood on 1 July 1948, or as first built, so earlier extensions may already have eaten the capacity you think you have. The boundary of what even counts as your property matters too — see what counts as curtilage.
Five prior-approval mistakes that catch homeowners
Almost every prior-approval problem I have seen comes back to one of five things. None of them is about the merits of your extension; all of them are avoidable.
- Assuming it’s a formality. The principle may be granted, but the detail is exactly what the council is there to scrutinise. Treat the application as something to be won, not ticked off.
- Starting work too early. If any part of the build begins before you have applied, the permitted development right is lost — and no later application can restore it.
- Banking on the clock. Deemed consent is real, but it turns on the council failing to notify you in time, and in our sample a third of decisions ran past 56 days. Confirm the exact expiry date before you act.
- Arguing the wrong points. On a larger home extension the only question is the impact on your neighbours; design is not in scope. Spend your effort on the matters the law actually lets the council weigh.
- Skipping the designation check. A conservation area, a National Landscape or an Article 4 Direction can remove the right entirely — in which case prior approval is irrelevant and you need full permission.
How this advice is generated
Statutory facts are cited to primary legislation and the April 2026 Planning Portal fee schedule. National figures are drawn from the Ministry of Housing, Communities & Local Government’s Planning Applications in England statistics. The project-type chart is original PlanWiser analysis of a compiled sample of 100 permitted development decisions across seven English local planning authorities — a sample, not a national dataset, and indicative rather than definitive. The from-practice case is a genuine, anonymised matter from the author’s local-authority casework, not a composite. The article was drafted with AI assistance, then reviewed and fact-checked by an MRTPI chartered town planner.
Data sources
- Town and Country Planning (General Permitted Development) (England) Order 2015 — Schedule 2 and article 7 (the rights, procedure and time limits).
- Town and Country Planning Act 1990 — ss. 57, 58, 78 and 192 (permission, appeals and lawful development certificates).
- Planning Portal fee schedule, 1 April 2026 (England) — statutory application fees.
- Gluck v Secretary of State [2020] EWCA Civ 1756 — extension of the determination period by written agreement.
- MHCLG, Planning Applications in England (Live Tables PDR1/PDR2) — national prior-approval volumes and outcomes.
- PlanWiser original analysis — a compiled sample of 100 permitted development decisions across seven English local planning authorities (indicative, not a national dataset).
Limitations of this guidance
- England only; Scotland, Wales and Northern Ireland have separate systems.
- Periods, fees and matters in scope vary by class and are subject to legislative change.
- Local circumstances and validation practice vary, and no outcome is guaranteed.
- This is general guidance, not a substitute for tailored professional advice on your site.
FAQs
Is prior approval the same as planning permission?
No. Prior approval is a lighter consent attached to specific permitted development rights. The principle of the development is already granted by the General Permitted Development Order, so the council only checks the particular matters the legislation allows it to check — for a larger rear extension that is the impact on your neighbours, while for a barn conversion under Class Q it includes highways, flooding, contamination, noise and whether the building is structurally capable of conversion. A full planning application is different: the council assesses the whole proposal against its development plan and can weigh any material consideration. Prior approval is also not a lawful development certificate, which simply confirms that something is already lawful. If you are unsure which route your project needs, the free Planning Quiz at planwiser.uk/take-the-assessment is a quick way to narrow it down before you spend anything.
What happens if the council does not decide my prior approval in time?
It depends on the right you are using. For a larger home extension the council has 42 days, and for most changes of use under Part 3 — such as Class Q or Class MA — it has 56 days. If it does not notify you of its decision within that period, you generally have deemed consent and can proceed in line with your application. The crucial word is notify: it is the council getting its decision to you in time that matters, not when it was signed off internally, so keep proof of what you received and when. One important exception is upward extensions to create new flats under Part 20, where there is no deemed consent at all — silence does not grant it. Never start work on the strength of an assumption; confirm the exact expiry date first.
How long does prior approval take?
The headline periods are 42 days for a larger home extension under Part 1, 56 days for most changes of use under Part 3, and eight weeks where the relevant right does not specify a period. Those are maximums for the council’s decision, not minimums — a straightforward application can be approved sooner. The period can only be extended if you agree to it in writing, which the Court of Appeal confirmed in 2020; until you do, the original clock keeps running. In practice the bigger variable is how complete your application is. If the council has to chase you for structural evidence, a flood risk assessment or a transport note, the timetable slips, so front-loading that information is the single best way to keep things short.
How much does a prior approval application cost in 2026?
From April 2026 the fee for most prior approval applications is £249 — that covers larger home extensions, additional storeys, agricultural and forestry development, demolition and solar. Where a change of use also involves building operations, such as Class Q, Class M or Class N, the fee is £536. Converting commercial premises in Use Class E to homes under Class MA costs £260 for each dwelling created, and a telecoms application under Part 16 is £610. If you submit through the Planning Portal there is also a service charge of £75.83 plus VAT. These are the statutory England figures; ignore older council pages still quoting £96, £120 or £240, which are out of date. To work out which right and fee apply to your project, the free Planning Quiz at planwiser.uk/take-the-assessment is a sensible first step.
Can I appeal if prior approval is refused?
Yes. A refusal of prior approval carries a right of appeal to the Planning Inspectorate, and so does a refusal of the principle where the council decides the development does not qualify for the right at all. You normally have a set period from the decision to appeal, and the inspector will look only at the matters the legislation puts in scope, so an appeal succeeds or fails on evidence about those specific issues rather than on the overall merits of the scheme. In many cases, though, the faster and cheaper route is to fix what the council objected to and resubmit — for example by supplying the structural report or revised design that was missing first time. Weigh the cost and delay of an appeal against a stronger second application before you commit.
Prior approval rewards people who treat it as a process, not a formality: know which clock you are on, prove your case before you apply, and never confuse council silence with a signed decision. Get those three things right and it is the fastest legitimate route to building — get them wrong and it is the quickest way to an enforcement file.
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Book the sessionHow this guide was researched
All statutory facts are cited to primary legislation and the current Planning Portal fee schedule. Practical points draw on the author’s local-authority and consultancy experience. England only. Subject to change. Updated June 2026.
Sources
- Town and Country Planning (General Permitted Development) (England) Order 2015 — legislation.gov.uk
- GPDO 2015, article 7 (time periods for prior approval decisions) — legislation.gov.uk
- Town and Country Planning Act 1990 — legislation.gov.uk
- Prior approval for extensions — Planning Portal
- Planning Applications in England statistics — MHCLG (GOV.UK)
