Non-determination appeals and when they actually help

A non determination appeal is available once the local planning authority has failed to issue a decision within the statutory period, under section 78(2) of the Town and Country Planning Act 1990. The right is real and it is used far less than the delays would suggest. That is usually the correct instinct, because lodging one converts a negotiation into an adversarial process and hands the decision to an inspector who has never seen the file.

The useful question is not whether the authority is late. It is whether the case is finished.

When the right to appeal arises

The prescribed periods sit in article 34 of the Development Management Procedure Order 2015: eight weeks from validation for most applications, thirteen weeks for major development, and sixteen weeks where the application is accompanied by an Environmental Statement. The clock runs from the date the application was valid, not the date it was submitted, which matters where validation was disputed.

Once the period expires without a decision, the applicant may appeal. The deadline is six months from the expiry of the period for most applications, and twelve weeks for a householder appeal. There is no deemed refusal in the sense of a notice arriving; the failure itself is the appealable event, and the appeal is lodged with the Planning Inspectorate in the usual way.

Two practical traps. The first is that the appeal has to be submitted within the window, and the window runs from expiry rather than from the point at which the relationship with the case officer broke down. The second is that an appeal against non determination bars any later appeal against a decision on the same application, because the authority's power to determine falls away.

Extensions of time and why they matter

A written agreement to extend the period removes the right to appeal for its duration. That is the whole function of the extension of time letter that authorities circulate at week seven.

Signing one is often sensible. It keeps the application alive while a consultee response is chased or a section 106 is drafted, and refusing to sign rarely accelerates anything, since an authority under pressure can simply refuse the application to avoid the performance consequence of a late decision.

What matters is the drafting. An open-ended extension to "such date as may be agreed" leaves you with nothing to press against. A dated extension, agreed to a specific milestone, keeps the right to appeal alive at the end of it. Where an authority asks for a second or third extension without movement on the substantive issues, the question of whether the case is actually progressing answers itself.

Keep the correspondence. If a costs application follows, the sequence of extension requests is the evidence.

What the council does once an appeal is lodged

Jurisdiction transfers. The authority can no longer determine the application, and its committee or delegated officer instead resolves what decision it would have made, which becomes the putative reasons for refusal set out in its appeal statement.

This has a curious effect. The authority is now free to assemble reasons without the discipline of a decision notice drafted at the time, and officers occasionally produce a longer list than they would have issued. An appellant who lodged partly to escape an unresolved highways objection may find the statement also raising design and amenity points that were never put in writing during the application.

The questionnaire arrives first, with the consultation responses, the site history and the relevant policies. Read it before drafting, because it shows which objections the authority is actually relying on and which consultee it is quietly ignoring.

The loss of a negotiated outcome

The strongest argument against a non determination appeal is that most applications are improved by the negotiation the appeal ends.

A case officer who is minded to support a scheme subject to a reduction in height, a revised access or an additional survey can deliver a permission with conditions. An inspector determines the scheme as submitted. There is no mechanism for the inspector to say "approve at four storeys instead of five", beyond the limited scope to accept minor amendments where no one is prejudiced.

So the appeal is right where the scheme is fixed and the disagreement is one of principle, and wrong where the remaining gap is a detail both sides could close. A consultant who lodges because the client is frustrated, rather than because the case is complete, usually spends the next six months explaining why the delay got longer.

Costs risk on both sides

Costs in planning appeals follow unreasonable behaviour rather than the outcome. The Planning Practice Guidance on appeals sets out the test, and both parties are exposed.

An authority that has delayed without explanation, failed to make a decision despite having all the information, or produced putative reasons for refusal it cannot substantiate on appeal is at risk. So is an appellant who appeals against non determination while the authority is still waiting for information the appellant was asked for months earlier, or who submits substantially amended plans with the appeal.

That second point deserves weight. Appealing while a request for further information sits unanswered is close to the clearest costs exposure available in the system.

Timing against a section 106

Where a scheme needs a planning obligation, the non determination appeal becomes harder to manage. The inspector cannot grant permission without the obligation in place, and negotiating a deed with an authority that is now the opposing party in an appeal is slower than negotiating with a case officer.

The practical answers are to complete the agreement before lodging, to submit a unilateral undertaking covering the obligations the authority has said it requires, or to seek an extension from the Inspectorate for the deed to be completed before the decision. A unilateral undertaking drafted without the authority's input risks being found not to meet the tests in regulation 122 of the Community Infrastructure Levy Regulations 2010, so it needs to be generous on the points that are agreed and clear about what is disputed.

On a major scheme with a contested affordable housing position, the obligation is usually reason enough to wait.

How inspectors handle an incomplete case

An inspector determines the appeal on the evidence before them, and where the authority never reached a view, there may be no officer report at all. That cuts both ways.

Without a report, there is no reasoned officer recommendation for the appellant to adopt, and the inspector has to work through the development plan from first principles. A thorough Planning Statement, setting out the policy assessment the officer never wrote, does more work on a non determination appeal than on any other type. Where a consultee objection was outstanding at the point of appeal, deal with it in the statement of case rather than hoping the consultee does not respond to the Inspectorate.

Procedural points matter too. Appeals are returned as invalid for avoidable reasons, and the causes are the same whether the appeal follows a refusal or a failure to decide, as covered in why the Planning Inspectorate returns appeals as invalid. If national policy shifts while the appeal is running, both parties can make further representations, which is the situation described in when national policy changes during your appeal. And third parties who commented on the application are notified and may participate, so the objections do not disappear with the transfer of jurisdiction, a point set out in how neighbours take part in a planning appeal.

When to wait instead

Wait where a consultee response is days away, where committee is scheduled within a few weeks, or where the officer has confirmed a recommendation of approval in writing. Wait where an obligation is part-negotiated. Wait where the objection is curable by a design change the client would accept.

Appeal where the authority has had everything for months and will not commit, where the officer recommendation is clearly negative and committee will follow it, or where the delay itself is costing more than the appeal.

The judgement is commercial as much as it is legal. An appeal through written representations takes months rather than weeks, and a hearing or inquiry longer, so the comparison is never appeal speed against decision speed. It is appeal speed against continued negotiation with an authority that has already shown what it can deliver.

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.

Browse the PlanScope report types to see which supporting documents an appeal statement will need to sit alongside.