Determination periods and what sets them

The planning determination period weeks you are working to depend on one thing: which scale category your application falls into. Eight weeks for a householder application or a minor scheme, 13 weeks for major development, and 16 weeks where the application is accompanied by an environmental statement. Those periods come from the Development Management Procedure Order 2015, and the clock starts the day after the authority receives a valid application rather than the day you press submit.

Major development is defined in the same order. Ten or more dwellings, or a residential site of 0.5 hectares or more where the number of units is not known, or a building or buildings with 1,000 m² or more of floorspace, or any site of one hectare or more.

The four periods and what triggers each

Prior approval is the odd one out, and it catches people. Several classes in the General Permitted Development Order set their own period and provide that the development is permitted if the authority does not notify a decision within it. That is a genuine deemed consent, which the main application regime does not have.

For a self-builder crossing from nine units to ten, the jump from eight to 13 weeks arrives alongside a longer validation list, an affordable housing requirement in many authorities, and the consultee referrals we set out in the statutory consultees that appear as a scheme grows. The determination period is the least of it.

When the clock starts and what stops it

Validation starts the clock, and validation is not automatic. The authority checks the application against the national requirements and its own local list, and an application missing a single item on that list sits as invalid until you supply it.

That is the most common cause of a programme slipping by three weeks for no visible reason. The fee has been paid, the drawings are uploaded, and the ownership certificate names the wrong party or the location plan has no north point. Nobody is working on the application and the clock is not running.

Things that do not stop the clock once it has started: a consultee asking for more information, the case officer going on leave, a neighbour objecting, a committee date being missed. The period runs regardless, and the authority either determines within it, agrees an extension with you, or is in breach.

Things that do stop it in practice: withdrawal and resubmission, which restarts everything, and a request from the authority for amended plans that amount to a different scheme, which usually leads to a fresh application rather than a revision.

Extensions of time and how to handle them

An extension of time is an agreement in writing between you and the authority to a longer period. Authorities ask for them constantly, and the request usually arrives in the last fortnight of the statutory period.

Agreeing is normally the right answer. The alternative is an authority facing a deadline it cannot meet, which leaves it choosing between a refusal it can issue on time and a permission it cannot. Officers under that pressure refuse.

Agree them on terms, though. Ask for a specific date rather than an open-ended extension, ask what has to happen in the extended period, and ask for the officer's recommendation in principle before you sign. An extension agreed in exchange for nothing is a free option for the authority.

Where a scheme has been extended twice and the officer still cannot say what is outstanding, something else is wrong. That is usually an unresolved consultee objection or an internal disagreement about the recommendation, and asking directly is better than extending a third time.

What happens when the period is missed

There is no deemed permission for a missed period on a main application. The application remains undetermined and you have a choice.

You can wait, which is what most applicants do and which is often right if the officer is close to a recommendation. You can appeal against non-determination, which transfers the decision to the Planning Inspectorate and removes it from the authority. Or you can ask for the fee back.

The appeal route has a real cost. You lose the chance to negotiate, the inspector decides on the material as submitted, and any amendment you wanted to make is largely off the table. On a scheme with an unresolved highways objection, an appeal against non-determination can be a way of getting a decision from someone who did not raise the objection. On a scheme where the officer supports you and is waiting for a committee slot, it throws away the support.

The fee regulations provide for a refund where the authority has failed to determine an application within 26 weeks, subject to conditions including that no extension of time was agreed. Check the current regulations for the detail, because both the fee figures and the refund provisions have been amended more than once.

Appeals and their own deadlines

Appeal deadlines are separate from determination periods and are easier to miss.

For a householder appeal the deadline is 12 weeks from the date on the decision notice. For most other appeals against refusal it is six months. For an appeal against an enforcement notice it is before the notice takes effect, which can be 28 days. These are hard deadlines, and the Inspectorate does not extend them for late instructions.

Where a refusal arrives and you intend to appeal, diarise the deadline the same day. Where you intend to resubmit instead, check whether a fee-free resubmission is available before the deadline passes, because losing the appeal right and the free resubmission at once is an expensive fortnight.

Performance agreements on larger schemes

For schemes at the top of the major category, a planning performance agreement is a project management document rather than a statutory device. It sets out the stages, who does what, the meeting dates, the consultee engagement plan and an agreed determination timetable, usually longer than 13 weeks, in exchange for named officer resource.

They work when both sides treat them as a programme. They fail when the authority charges for one and the timetable slips anyway with no consequence.

For a scheme of ten to fifty units a performance agreement is usually unnecessary. What helps more at that scale is pre-application advice with the consultees present, and a submission that answers the local validation list line by line. Where an Environmental Impact Assessment is involved, the 16-week period and the screening and scoping stages before it change the programme completely, and the environmental statement has to be prepared by competent experts under the EIA Regulations 2017.

Programming around the real timescale

Plan against outcomes rather than statutory periods. A realistic programme for a ten-unit scheme in England runs something like this:

1. Pre-application advice: four to eight weeks from request to written response.
2. Survey work with seasonal constraints, such as bat emergence surveys between May and September, which can dictate everything else.
3. Preparation and validation: two to four weeks, assuming the local list is met first time.
4. Determination: 13 weeks statutory, commonly extended by four to eight weeks on a scheme with any complexity.
5. Discharge of pre-commencement conditions: eight weeks per application, and there may be several.

Step five is the one that gets left out of finance appraisals. A permission with six pre-commencement conditions is not a start on site, and a condition requiring approval of a construction method statement can add two months after the permission is issued.

Write the Planning Statement to answer the validation list explicitly, because validation delay is the only part of this timeline entirely within your control. Enter your postcode on PlanScope to see which reports a scheme of your size is likely to need.

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.