Extensions of time: when to agree one and when not to

Article 34 of the Development Management Procedure Order 2015 gives a local planning authority eight weeks to determine most applications, 13 weeks for major development and 16 weeks where an environmental statement has been submitted. Those periods can be extended only by written agreement between the applicant and the authority. Agreeing costs you the right to appeal for non-determination while the extension runs, and it may cost you the fee refund under the planning guarantee.

Most agents agree as a reflex. The better habit is to ask one question first: what specifically is the extension buying?

Why councils ask for an extension of time

Some of the reasons are honest and some are administrative, and it helps to know which you are dealing with.

The honest ones are that a statutory consultee has not replied, that a section 106 agreement is still in drafting, that amended plans have arrived and need re-consultation, or that the case is going to a committee whose next meeting falls after the deadline. Each of those has a date attached.

The administrative one is performance. Authorities are measured on the proportion of applications determined within the statutory period, and applications with an agreed extension of time are treated differently in that measurement. A council facing designation for poor performance has a direct interest in extensions, and a case officer asking for one in week seven with no obstacle named is usually managing a statistic.

Neither motive is improper. But they justify different answers.

What you give up by agreeing

Three things, in descending order of importance.

The right to appeal for non-determination under section 78 of the Town and Country Planning Act 1990 falls away for the length of the extension. That is the whole point of the agreement from the council's side, and it is the only real pressure an applicant has.

The fee refund may go with it. The planning guarantee provides for a refund of the application fee where the authority has not determined the application within 26 weeks, and the Fees Regulations treat an agreed longer period differently. On a major application the fee is a substantial sum, so read the current regulations rather than assuming.

And you lose momentum. A case that slips past its date tends to slip again, because the officer's workload has already moved on to whatever is now in week seven.

The 26-week planning guarantee

The guarantee is worth understanding properly, because it is the one financial consequence a council actually feels. It refunds the fee where a decision has not been issued within 26 weeks of the start date.

Two practical points. It is a refund of the fee only, not of your costs, so on a householder application it is a small sum and on a major it is not. And it does not oblige the authority to decide, so it is a remedy rather than a lever.

Where an application is drifting towards 26 weeks, the useful move is to write to the head of development management, copying the case officer, setting out the chronology and asking for a determination date. That letter tends to produce a decision more reliably than the refund does.

Using a deadline to unblock a consultee

The most productive extensions are short, dated and conditional. If the lead local flood authority has not commented, agree four weeks and say in the email that the extension is to allow that response, and that you will expect a decision within a fortnight of it arriving.

That framing does three things. It gives the officer cover to chase the consultee with a date attached. It stops the extension being used for something else. And it creates a written record that helps if the case later goes to appeal on delay.

Where the obstacle is a consultee who has objected rather than one who is silent, an extension is more valuable still, because the alternative is a refusal you then have to appeal. Use the time to get the technical answer, and where the objection is on drainage, transport or ecology, that means a specific piece of evidence rather than a covering letter. The full list of supporting report types is a reasonable prompt for what the consultee is likely to want.

Drafting the agreement

Nothing formal is needed. An exchange of emails satisfies the requirement for a written agreement, and shorter is better.

1. State the application reference and the current statutory expiry date.
2. State the new date, as a date rather than a number of weeks.
3. State the reason in one line.
4. Say that any further extension requires a fresh agreement.
5. Ask the officer to confirm by reply.

Put the date in the subject line. Six months later, when the case has changed officers twice, that subject line is how anyone finds the agreement.

Avoid two forms of words. An extension "until the application is determined" is not an extension, it is a surrender. And an extension agreed "in principle" on a phone call is worth nothing when the file moves.

One more habit worth adopting on major applications: keep a single running note of every extension, its date and its stated reason, and send the officer a copy each time you agree a new one. It is a courtesy, and it makes the pattern visible to whoever picks the case up next. Where an application has run through four extensions for four different reasons, that note is also the chronology an inspector will want if costs are ever in play.

When to refuse and appeal instead

The calculation is a commercial one, and it turns on three things: whether the council has effectively decided, what the delay costs, and how strong the case is.

Refusing an extension makes sense where the officer has signalled a recommendation of refusal and is simply waiting for a committee slot, where the objection is one you cannot design out, or where a funding deadline makes six more months worthless. In those cases the appeal was coming anyway, and starting it earlier is the cheaper route.

The counter-argument is procedural. On a non-determination appeal you lose the officer's report, which on a marginal case often contains findings in your favour on the issues the council did not pursue. You also lose the chance of a late change of heart, which happens more often than agents expect once a consultee withdraws an objection.

It rarely makes sense where the officer is supportive, where a section 106 is in drafting, or where the delay is caused by evidence you have not yet supplied. Appealing for non-determination in those circumstances hands the case to an inspector who has no officer report to work from and a council whose putative reasons for refusal will be drafted specifically for the appeal.

Illustrative example: a nine-unit scheme reaches week 13 with a supportive officer report drafted and a highways response outstanding. Agreeing six weeks costs almost nothing. The same scheme at week 20, with the officer recommending refusal on character grounds and a committee date not yet set, is one where the appeal clock should already be running.

Whichever route you take, keep the Planning Statement current, because a document written for validation reads badly at appeal if the policy position has since moved. Reform of the determination framework continues, and the planning law timeline is a reasonable place to keep an eye on changes to the periods and the guarantee.

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.