Prior approval periods and when consent is deemed given
Deemed consent is a real right, but it only approves the details you submitted and it only runs if the application was valid on the day it arrived.
For most prior approval applications under Schedule 2 to the GPDO 2015 the local planning authority has 56 days from the day the application is received, and if it neither grants nor refuses within that period the development may proceed in accordance with the details submitted. That is the prior approval deemed consent period, and it is a real right rather than a technicality. It is also easier to lose than most people realise, because the 56 days only ever ran if the application was valid on the day it arrived.
How the period is counted
The period begins with the day the authority receives the application, not the day it validates it, and not the day it acknowledges it. That distinction is the reason evidence of receipt matters so much.
Fifty-six days is the standard period across most of the commonly used classes, including the commercial to residential route in Part 3 and the agricultural building conversions. Some classes are different. The larger home extension procedure in Part 1 runs on a shorter period, and the agricultural determination procedure in Part 6 is shorter again.
Always read the class. The period, the matters the authority may consider, the consultation requirements and the time limit for completing the development are set out within each class and they vary.
| Route | Typical determination period | Notes |
|---|---|---|
| Part 3 commercial to dwellinghouses | 56 days | Prior approval on a defined list of matters |
| Part 3 agricultural building to dwellinghouses | 56 days | Separate limits on floorspace and unit numbers |
| Part 1 larger home extension | Shorter period under the neighbour consultation scheme | Only engaged if a neighbour objects |
| Part 6 agricultural development | Shorter determination of whether prior approval is required | Two-stage process |
| Part 16 electronic communications | 56 days | Different matters for consideration |
Treat the table as a prompt to check the current text of the Order rather than as the answer. The GPDO has been amended many times and the classes move.
What starts the clock
Three things have to be right for the period to begin.
The application has to be in the form the class requires, with the specified plans, drawings and information. The fee has to be paid. And it has to be received by the authority.
An application missing a required document does not start the period, and an authority that later says so is usually right. This is where deemed consent claims fail most often, and it is why the first step is always a line by line check against the class text of what the application must contain.
So submit through the planning portal or by a route that generates a dated receipt, keep the acknowledgement, and keep the payment confirmation. The evidence costs nothing at the time and is impossible to reconstruct later.
Deemed consent and the conditions attached to it
Where the period expires without a decision, the development may be begun, but only in accordance with the details submitted with the application.
That qualification is the whole of the risk. Deemed consent does not approve a scheme you would like to build. It approves the drawings you sent. A change to the fenestration, the layout, the parking or the materials after the period expires is outside the consent.
The conditions and limitations in the class itself still apply as well. Time limits for completing the development, restrictions on subsequent changes, and any requirement to notify the authority on completion all survive the deemed consent. Read the class again before starting on site.
Where the authority fails to notify you
The obligation is on the authority to notify the applicant of its determination within the period. Disputes usually turn on whether a decision was made and sent in time, and on whether it reached you.
Keep a dated log. Note the day the application was received by the authority, the day the period expires, and every communication in between. If the period expires, write to the authority the following working day stating that you consider prior approval to be deemed granted, setting out the date of receipt and the expiry date, and asking them to confirm.
They may disagree. That letter is still worth sending, because it fixes your position and it forces the authority to say why it thinks the period did not run.
The risks of relying on deemed consent
Deemed consent is legally effective, but it is harder to prove than a decision notice, and it becomes a problem at the point of sale or refinancing rather than at the point of construction.
A solicitor acting for a buyer will ask for evidence that permitted development rights applied to the building, that the application was valid, that the period expired and that the works accord with the submitted details. A folder of emails is not a comfortable answer.
The usual solution is to apply for a certificate of lawfulness for existing use or development under section 191 of the Town and Country Planning Act 1990 once the works are complete. It converts an argument into a formal document. Some lenders effectively require it.
There is also the Article 4 question. Permitted development rights, including prior approval routes, can be withdrawn by an Article 4 direction, and many authorities have made directions covering the commercial to residential route in defined areas. Check the direction before you rely on the right at all. The wider procedural picture is set out in what happens in the eight weeks after validation, which covers the ordinary application route alongside this one.
Evidence to retain
- The submitted application with every plan and document, in the form sent, with the transmission receipt.
- The fee payment confirmation.
- The authority's acknowledgement, and any validation correspondence.
- Your dated calculation of the expiry date.
- The letter you sent on expiry, and any reply.
- Photographs of the building before works began.
Keep them together and keep them for the life of your ownership. This is the file a future conveyancer will want.
Checking the position before starting works
Before a machine arrives, confirm four things. That the building and the use were eligible under the class on the relevant date. That no Article 4 direction or condition on an earlier permission removed the right. That the period has expired with no decision notified. And that what you intend to build matches the submitted details exactly.
If any of those is uncertain, the honest advice is to wait and take advice rather than to start. Building in reliance on a deemed consent that turns out not to exist is an enforcement problem, not a paperwork problem. An extension of time agreement is also worth knowing about, since authorities sometimes ask for one on prior approval applications and agreeing to it restarts your calculation.
Where the position remains unclear, the certificate of lawfulness route under section 192 for proposed development gives you an answer before you spend money. Set the argument out in a Planning Statement with the dates and the class text.
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.
Frequently asked questions
How long does a prior approval application take?
For most commonly used classes the authority has 56 days beginning with the day the application is received. Some routes differ: the larger home extension procedure and the agricultural determination procedure under Part 6 both run on shorter periods. Read the text of the specific class, because the periods and the matters for consideration vary.
When does the prior approval period start?
On the day the authority receives the application, not the day it validates or acknowledges it. The period only runs if the application was complete in the form the class requires, with the specified plans and information, and if the fee was paid. A missing required document means the clock never started.
Can I build anything once the period expires?
Only what you submitted. Deemed consent authorises development in accordance with the details sent with the application, so changes to layout, fenestration, parking or materials fall outside it. The conditions and limitations in the class itself, including any time limit for completing the development, continue to apply.
How do I prove a deemed consent later?
Apply for a certificate of lawfulness for existing use or development under section 191 of the Town and Country Planning Act 1990 once the works are complete. It converts a bundle of correspondence into a formal document, which is what a buyer's solicitor or a lender will want to see. Keep the submission, the receipt, the fee confirmation and your expiry calculation.
Can prior approval rights be removed?
Yes. An Article 4 direction can withdraw permitted development rights, including prior approval routes, in a defined area, and many authorities have made directions covering commercial to residential conversion. Conditions on an earlier planning permission can also remove rights. Check both before relying on the class at all.
Sources and further reading
This article is general guidance about the planning system in England and, where stated, the rest of the UK. It is not legal or professional advice. Check your local planning authority’s validation requirements and take professional advice for your specific site.