Planning conditions: the six tests and how to challenge one
Knowing which of the six tests a condition fails decides whether you negotiate, vary it under section 73 or appeal. The routes compared, with the risk in each.
A planning condition has to pass six tests: it must be necessary, relevant to planning, relevant to the development permitted, enforceable, precise, and reasonable in all other respects. National guidance on the use of planning conditions sets them out, and a condition that fails any one of them is vulnerable. Knowing which test a condition fails is the difference between a productive conversation with the case officer and a wasted appeal.
Most conditions that cause trouble fail on precision or on necessity. Very few fail on relevance, because officers rarely impose conditions about things that have nothing to do with the scheme.
The six tests applied in practice
Necessary means the permission would have to be refused without the condition. A condition that merely improves the scheme, or restates something already controlled by other legislation, is not necessary. Requiring compliance with the Building Regulations is the standard example.
Precise means the applicant can tell, reading the condition alone, exactly what has to be done and when. Conditions requiring works to be carried out to the satisfaction of the local planning authority, with no criteria, fail this test and are unenforceable in practice.
Enforceable means a breach could be identified and acted on. A condition requiring an occupier to behave in a particular way inside their home usually fails here.
Reasonable in all other respects covers the residue, including conditions that would make the development physically impossible or commercially unviable, and conditions requiring payment of money, which belong in a section 106 obligation rather than on the decision notice.
The underlying legal tests come from case law and are narrower still: a condition must serve a planning purpose, fairly and reasonably relate to the development permitted, and not be so unreasonable that no reasonable authority could have imposed it.
Written agreement before a pre-commencement condition
Section 100ZA of the Town and Country Planning Act 1990 prevents a local planning authority from imposing a pre-commencement condition without the written agreement of the applicant. The procedure is prescribed: the authority gives written notice of the proposed condition with its text and the reasons for it, and the applicant has a period of 10 working days to respond.
Two things follow. Silence is not safety, because failing to respond within the period allows the condition to be imposed. And the notice is an opportunity, since the applicant can propose alternative wording, suggest a different trigger such as before first occupation, or agree the condition with a shorter list of required details.
Read those notices the day they arrive. They often land during determination when attention is elsewhere, and the 10 working days pass quickly.
Conditions that are void for uncertainty
A condition can be so imprecise that it has no legal effect. The usual candidates:
- Requirements expressed by reference to a document that is not identified by title and date.
- Conditions requiring something to be agreed with a third party who has no statutory role.
- Conditions with no compliance date and no trigger.
- Conditions that contradict another condition on the same notice.
- Conditions that purport to restrict the use of adjoining land outside the applicant's control.
A void condition does not automatically invalidate the permission, but the position depends on whether the condition was fundamental to the grant, which is a question about whether the condition can be struck out and the permission left standing.
Appealing a condition without losing the permission
Here is the trap. An appeal under section 78 against a condition puts the whole application before the inspector, who deals with it as if it had been made to them in the first instance. In principle the permission can be refused outright, and the appellant ends with nothing.
In practice inspectors rarely take that course on a straightforward condition appeal, but the risk is real enough that it changes the advice. Where the underlying permission is valuable and the condition is irritating rather than fatal, the safer route is usually a section 73 application.
Timescales differ too. A condition appeal runs on the ordinary appeal timetable, while a section 73 application is determined by the council in the normal period, with a further appeal available if refused. In the small number of authorities designated for poor performance, applications can also go direct to the Planning Inspectorate, a route explained in applying direct to the Planning Inspectorate under section 62A.
Varying a condition under section 73
Section 73 allows an application to develop without complying with a condition previously imposed. If granted, the result is a new planning permission sitting alongside the original, with its own conditions and its own reference number.
Points that matter:
- The description of development cannot be changed through section 73, so a variation that alters what is permitted needs a fresh application.
- The council can impose different conditions on the new permission, including ones you did not ask about, so review the draft notice.
- The original permission survives, which is useful if the section 73 is refused.
- Community Infrastructure Levy liability can be recalculated on the new permission, which occasionally produces an unwelcome surprise.
- The Levelling-up and Regeneration Act 2023 introduced a separate route for minor variations under section 73B, with commencement to be verified before relying on it.
For trivial changes, a non-material amendment under section 96A is quicker, though the council decides what counts as non-material and there is no appeal against a refusal.
An illustrative example
Illustrative only: a permission for a rural workshop carries a condition requiring a landscaping scheme to be submitted and approved before commencement, and a second condition limiting hours of operation to 08:00 to 18:00 Monday to Friday.
The landscaping condition is a reasonable pre-commencement requirement, and the operator agrees revised wording moving the trigger to before first occupation so that groundworks can start. The hours condition is the commercial problem, because the business needs Saturday mornings. That goes to a section 73 application supported by evidence on traffic and noise at weekends, leaving the original permission intact while the council considers it.
Two different problems, two different routes, one decision notice.
Grampian conditions and their limits
A Grampian condition is negatively worded and prevents development until something happens, typically off-site works on land the applicant does not control. They are lawful, and the courts have accepted that such a condition may be imposed unless there is no prospect at all of the action being performed within the lifetime of the permission.
The practical limit is commercial rather than legal. A condition tied to a highway agreement with a third party landowner can leave a permission unimplementable, and once the time limit expires the permission lapses. Test the deliverability before accepting the wording.
Reading a decision notice for traps
Work through the notice methodically. Identify which conditions are pre-commencement, which are pre-occupation and which are compliance conditions running for the life of the development. Check the approved plans condition lists every drawing you intend to build from, with the correct revision letters. Note any condition requiring details to be submitted, and count the discharge applications and fees you will need.
Then check the consistency between conditions and the description of development, and between the conditions and any section 106 obligation. Where the notice imposes an obligation the scheme cannot meet, raise it in writing immediately rather than after implementation, a point that also applies to enforcement correspondence generally, as set out in planning contravention notices and how to answer one.
Time-limited permissions carry their own arithmetic, explained in temporary permissions and what happens when they expire. Where you are drafting the case for a variation, the Planning Statement should address the six tests directly rather than arguing the merits of the scheme again.
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.
Frequently asked questions
What are the six tests for a planning condition?
A condition must be necessary, relevant to planning, relevant to the development to be permitted, enforceable, precise, and reasonable in all other respects. National guidance on the use of planning conditions sets them out. Conditions most often fail on precision, where the requirement cannot be understood from the wording alone, or on necessity, where permission would not have been refused without them.
Can a council impose a pre-commencement condition without my agreement?
Not under section 100ZA of the Town and Country Planning Act 1990. The authority must give written notice of the proposed condition and its reasons, and the applicant has 10 working days to respond. Failing to respond allows the condition to be imposed, so treat the notice as a deadline and use it to propose alternative wording or a later trigger.
Is it risky to appeal against a single condition?
There is a real risk. A section 78 appeal against a condition puts the whole application before the inspector, who determines it as if it had been made to them at first instance, so in principle the permission could be refused. Inspectors rarely do so on a straightforward condition appeal, but where the permission is valuable a section 73 application is usually safer.
What can a section 73 application change?
It allows development without complying with a condition previously imposed, and if granted it creates a new permission alongside the original. The description of development cannot be altered by this route. The council may impose different conditions on the new permission, and levy liability can be recalculated, so read the draft decision notice carefully.
What is a Grampian condition?
A negatively worded condition preventing development until something happens, usually off-site works on land the applicant does not control. The courts accept them unless there is no prospect at all of the action being performed within the life of the permission. The practical risk is that an undeliverable trigger leaves the permission unimplementable until it lapses.
Sources and further reading
This article is general guidance about the planning system in England and, where stated, the rest of the UK. It is not legal or professional advice. Check your local planning authority’s validation requirements and take professional advice for your specific site.