The six tests a planning condition has to meet

A planning condition has to pass six tests before a local planning authority can properly impose it. It must be necessary, relevant to planning, relevant to the development permitted, enforceable, precise, and reasonable in all other respects. Those are the tests for planning conditions set out in national Planning Practice Guidance, and the first three of them came from the courts long before they were written into guidance. If a condition fails any one of them, it is vulnerable, and the route to changing it is usually cheaper and faster than applicants expect.

Most agents meet the tests at the wrong moment: after the decision notice has landed, when a condition turns out to be undischargeable. The better moment is the week before the officer writes their report.

Where the tests come from

The power to impose conditions sits in section 70(1)(a) of the Town and Country Planning Act 1990, which lets an authority grant permission subject to "such conditions as they think fit". That looks wide. It is not, because the courts read it narrowly.

In Newbury District Council v Secretary of State for the Environment, the House of Lords set out three requirements: a condition must be imposed for a planning purpose and not an ulterior one, it must fairly and reasonably relate to the permitted development, and it must not be so unreasonable that no reasonable authority could have imposed it. Those three became the backbone of the six. Planning Practice Guidance on the use of planning conditions then added precision, enforceability and necessity as separate headings, which is a useful split because the failure modes are different.

The guidance also carries a model list of conditions and, more usefully, a list of conditions that should not be used at all. Read that second list before you argue about wording, because officers often lift conditions from a template without checking whether the template still holds.

Necessary and relevant to planning

Necessity is the test that kills the most conditions on appeal. The question is not whether the condition is helpful but whether permission would have to be refused without it. If the development is acceptable anyway, the condition is unnecessary and should go.

Relevance to planning means the condition has to serve a planning purpose. Controlling who occupies a building can be a planning matter where occupancy goes to the policy justification, for example an agricultural occupancy condition or an affordable housing tenure restriction. Controlling a private dispute between neighbours is not. Nor is a condition that duplicates other legislation: a condition requiring compliance with the Building Regulations, or with the Control of Pollution Act, adds nothing and fails on necessity.

Watch for conditions that try to do the work of a section 106 obligation. Financial contributions cannot be secured by condition. Where an officer has drafted a condition requiring a payment, that condition is unlawful and needs to move into an agreement or come out.

Relevant to the development permitted

This is the test people confuse with the last one, and the distinction matters. A condition can serve a perfectly good planning purpose and still fail because it has nothing to do with the scheme in front of the authority. Requiring highway works on a road half a mile away, unconnected to the traffic the development generates, is the classic example.

The practical version of the test is a sentence you should be able to write without straining: this condition is needed because of something this development does. If the sentence needs two links in the chain, the condition is probably too remote.

Off-site works are not automatically caught. Where a scheme creates the need for a crossing or a drainage outfall, a properly drafted condition can require it, usually as a Grampian condition preventing occupation until the works are complete. The limit is that a Grampian condition must have a reasonable prospect of being satisfied within the life of the permission. If the land is in third-party ownership and the owner has refused, the condition fails.

Enforceable and precise

A condition is enforceable if a breach can be detected and acted on. It is precise if the applicant can read it and know exactly what to do. These two collapse into one working question: could a case officer standing on site with the decision notice say yes or no?

Vague verbs are the usual culprit. Conditions requiring a scheme to be "appropriately landscaped", "suitably screened" or "carried out to a high standard" are unenforceable because nobody can say when they have been met. So are conditions requiring works to be done "to the satisfaction of the local planning authority" without a mechanism, which the guidance discourages.

Compare the two drafting styles:

Precision also protects the applicant. A tightly drawn condition has an end point. A loose one leaves the authority free to keep asking.

Reasonable in all other respects

The sixth test catches conditions that pass the rest and still go too far. A condition that makes the permission impossible to implement is unreasonable. So is one that requires the applicant to give up land or rights without compensation, or one whose cost is out of proportion to the harm it addresses.

Pre-commencement conditions deserve their own paragraph here, because the law changed. Section 100ZA(5) of the Town and Country Planning Act 1990, inserted by the Neighbourhood Planning Act 2017 and brought into effect with the Town and Country Planning (Pre-commencement Conditions) Regulations 2018, means an authority cannot impose a pre-commencement condition on most applications without the applicant's written agreement. There is a notice procedure, and a deemed agreement if the applicant does not respond in time. Agents who know the procedure use it to move conditions from "before development starts" to "before above-ground works" or "before first occupation", which can save a build programme several weeks.

Conditions that fail and what happens

A bad condition does not make the permission bad. The usual position is that the condition can be severed, and the permission stands without it, although the courts have treated a condition as fundamental in a small number of cases.

Three routes exist for getting rid of one:

1. Appeal the condition under section 78 of the Town and Country Planning Act 1990 within six months of the decision, or 12 weeks for a householder application. The risk is that the whole permission is reconsidered.
2. Apply under section 73 to vary or remove the condition. The authority considers only the condition, and a new permission is issued with the rest unchanged. This is the ordinary route.
3. Apply under section 96A for a non-material amendment where the change is trivial, though this is a poor fit for substantive conditions.

If the condition is one you cannot discharge because it was drafted badly, say so in writing to the case officer first. Many are corrected by agreement without any application at all, particularly where the wording was lifted from a template and nobody intended the effect.

Negotiating wording before decision

The least costly fix is the one made before the decision notice is issued. Ask the case officer for draft conditions when the recommendation is being written, and offer wording yourself. Officers are usually receptive, because a condition they have to defend at appeal is a condition they would rather get right.

Three things are worth checking in that draft. Are the approved drawings listed by number and revision, so that later amendments have something to amend. Are any pre-commencement conditions genuinely pre-commencement, or could they be tied to a later trigger. And does each condition carry a reason that matches a policy in the development plan, because a reason that cites nothing is a condition with a weak footing. The weight given to the development plan under section 38(6) runs through condition reasons as much as through the decision itself.

Keep a note of what you agreed and with whom. When a different officer handles the discharge application 14 months later, that note is the only record of what the condition was meant to achieve.

An illustrative case: a 1930s semi with a rear extension was granted permission subject to a condition requiring obscure glazing to a flank window "at all times". The window was on the ground floor, facing a 2m fence. The condition was unnecessary, and it came out on a section 73 application for the standard fee, four weeks later. Nobody had read it before the decision was issued.

Drafting conditions well is a drafting job, not a policy job, and it rewards the person who reads the decision notice line by line. If you are assembling the supporting documents for an application, PlanScope can draft the Planning Statement that sets out your policy case, and you can see the full set of 66 report types by category before you decide what the authority will expect. Understanding how a fall-back position works as a material consideration often shapes what conditions an officer thinks they need, and the statutory footing for the whole exercise sits in section 38(6) and the development plan.

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.