Precedent in planning decisions and how to use it

Planning precedent does not work the way people expect. There is no doctrine of binding precedent in the planning system: a decision on one application does not oblige the council to decide the next one the same way, and the phrase officers use, that each case is determined on its own merits, is an accurate statement of the law. What does exist is a duty to be consistent, and consistency is a material consideration that can be argued either for you or against you.

The distinction matters because a householder who walks into a planning office with a photograph of a similar extension three doors down is making a real point, badly.

Why planning has no binding precedent

Section 38(6) of the Planning and Compulsory Purchase Act 2004 requires applications to be determined in accordance with the development plan unless material considerations indicate otherwise. Section 70(2) of the Town and Country Planning Act 1990 sets out what the authority must have regard to. Neither provision mentions previous decisions, and no statute makes one decision binding on another.

There are good reasons for that. Sites differ in ways a photograph does not capture: the relationship to a neighbour's windows, the ground level difference across a boundary, the position of a protected tree. Policies change, so a permission granted under a superseded local plan may have been correct then and wrong now. And a council that had to repeat its earlier decisions would be locked into its worst ones.

The result is a system with a strong internal pull towards consistency and no rule requiring it.

Consistency as a material consideration

The leading authority is North Wiltshire District Council v Secretary of State for the Environment, decided in 1992, which established that a previous appeal decision on the same or a similar issue is a material consideration and that a decision maker departing from it must give reasons for doing so. Inconsistency without explanation is a ground of challenge.

In practice this means the officer writing your report is expected to deal with a comparable case you have put in front of them. They may deal with it by distinguishing it, by explaining that policy has changed, or by accepting the comparison and following it. What they may not do is ignore it, and a delegated report that fails to mention a directly comparable approval raised in representations is weak.

The pull is strongest on appeal, where inspectors are conscious that the Planning Inspectorate should not produce contradictory decisions on the same street.

Using a nearby approval in your own case

Three things make a comparison usable.

Proximity in policy terms. A permission granted under the current local plan carries far more weight than one granted in 2009 under a plan that has since been replaced. Check the adopted date of the plan that was applied.

Similarity of the point in issue. The comparison has to bear on the reason your scheme is in doubt. If the officer's concern is the depth of a rear extension against a neighbour's kitchen window, an approval for a similar depth on a plot with no neighbouring window is not a comparison at all.

Evidence in the right form. A photograph proves nothing. The application reference, the decision notice, the approved drawings and the delegated report are what an officer can read and cite.

Set the comparison out in the planning statement rather than in an email. One short section, with a table of the reference numbers, the decision dates and the relevant dimensions, does the work.

Distinguishing an approval that hurts you

The same technique runs in reverse when an objector produces an approval you would rather not discuss, or when the council points at a refusal nearby.

Look first at the date and the policy background. Then at the physical differences: orientation, levels, separation distances, boundary treatment, the presence of an intervening building. Then at the assessment itself, because approvals are sometimes granted on a basis that no longer applies, for example before an Article 4 direction removed permitted development rights in the area or before a conservation area was designated.

Where a local design code has been adopted since the earlier decision, the parameters it fixes will often explain the difference directly, as set out in what a design code fixes and what it leaves open.

When precedent is a reason for refusal

Councils sometimes refuse on the basis that granting permission would set an undesirable precedent. That is a legitimate consideration, but only where there is evidence that similar proposals would be likely to follow and that the cumulative effect would cause harm. The courts have made clear that a bare fear of precedent, unsupported by evidence, is not a sound reason for refusal.

The test is practical. Are there other sites in the area capable of making the same application? Would the council find it difficult to resist them? Would the accumulation of such developments change the character of the area or overload an infrastructure constraint? A reason for refusal that answers those questions with facts is durable. One that simply asserts the risk usually falls at appeal.

This is where cumulative harm arguments belong for objectors as well. If a street has already lost four front gardens to hardstanding and a fifth application is before the council, the point to make is the cumulative effect on drainage and street character, with the four references listed.

The weight of appeal decisions

Inspectors' decisions are indicative rather than binding. They show how the Inspectorate has approached a particular policy test on comparable facts, which is useful, and they are freely searchable through the Inspectorate's appeals casework service.

Weight varies. A recent decision on a site in the same borough, applying the same local plan policy, is worth quoting at length. A decision from another region on different policy wording is worth a sentence. A recovered or called in decision by the Secretary of State carries more weight than a written representations appeal on a garage conversion. And a High Court judgment on the interpretation of a policy is different in kind, because that is binding law on what the words mean.

Do not overstate what a decision says. Quote the paragraph, give the appeal reference and the date, and let the inspector's words carry the argument. Officers check.

Presenting comparable cases

A comparison schedule beats prose. For each case give the application reference, the address, the decision date, the decision, the relevant dimension or policy point, and one line on why it is comparable.

An illustrative example. A homeowner wants a two storey side extension with a 900 millimetre gap to the boundary, and the council's design guide asks for one metre. Two approvals in the same ward in the past three years allowed 900 millimetres where the flank wall faced a garage rather than a habitable room. Listing those references, with the approved plans attached and the common feature identified, gives the officer a basis to approve. The photograph of a bigger extension somewhere else in the town does not.

Where the route in question is prior approval rather than a full application, the comparison has to be limited to the matters the council may lawfully consider, which we cover in what the council may consider at prior approval.

Precedent will not win an application on its own. It shifts the burden, and on finely balanced householder cases that is often enough.

Enter your postcode on PlanScope to see which supporting documents your application needs, then set out your comparable cases in the planning statement where the officer will read them. PlanScope provides AI-assisted draft reports for planning applications. Reports should be reviewed before submission. We do not guarantee planning approval.

This is general guidance, not legal advice; check the position with your local planning authority or a qualified professional before relying on it.