Material operations and the moment development begins

Development is treated as begun on the earliest date on which a material operation is carried out, and section 56(4) of the Town and Country Planning Act 1990 lists what counts. The list is short and specific: work of construction in the course of erecting a building, work of demolition, digging a trench to contain the foundations, laying an underground main or pipe to those foundations or to that trench, any operation in the course of laying out or constructing a road, and any change of use amounting to material development. Material operations section 56 questions almost always arise for one reason, which is a permission about to expire.

The answer matters because a permission not implemented within its time limit is gone, and nothing brings it back.

Why the start date matters

Three consequences hang on the date, and they are not the same thing.

A full planning permission is subject to a condition under section 91 requiring development to begin within three years of the grant, or such other period as the permission specifies. An outline permission runs under section 92, with an application for approval of reserved matters required within three years and the development to begin within two years of the final approval of reserved matters, subject to the terms of the permission.

The Community Infrastructure Levy regime depends on it too. A commencement notice has to be submitted to the collecting authority before development begins, and failure to do so can mean the loss of a self-build or residential extension exemption and the imposition of a surcharge. That is a separate deadline from the planning one and it catches people who got the planning side right.

And enforcement time limits run from substantial completion or from the breach rather than from the start, so the start date is not a shield. It establishes that the permission was implemented, nothing more.

The statutory list of material operations

Read the list literally, because the courts have.

Digging a trench to contain the foundations qualifies. Digging a trial pit to investigate ground conditions does not, because it is not a trench to contain the foundations. Laying out or constructing a road qualifies, and the courts have accepted modest works of that kind as sufficient where they formed part of the permitted scheme.

Two general limits apply across all of them. The operation must be part of the development permitted, so works for some other purpose do not count however substantial. And the operation must not be so trivial as to be disregarded, which is a question of degree rather than a threshold. The de minimis question comes up repeatedly across planning judgements and the approach is set out in de minimis in planning judgments.

A token start is lawful if it is a real material operation forming part of the permitted development. It is also a hostage, because the permission then remains implementable indefinitely while the site sits with an unfinished trench, and a later completion notice is the authority's remedy.

What does not count as a start

The list below is not exhaustive and it covers what people most often rely on wrongly.

• Site clearance, vegetation removal and levelling, unless the levelling is itself part of laying out a road or excavating foundations.
• Erecting site hoarding, fencing or a site cabin, which are temporary works under Part 4 of the General Permitted Development Order rather than part of the permitted development.
• Trial pits, boreholes and site investigation.
• Marking out the building footprint with pegs or paint.
• Delivery of materials to the site.
• Demolition, where demolition does not form part of the permitted development, although demolition that is part of the scheme does qualify.

The last one is worth dwelling on. Where the permission is for redevelopment including demolition, demolishing the existing building is a material operation. Where the permission is for an extension and the owner demolishes an unrelated outbuilding, it is not.

Pre-commencement conditions and lawful implementation

This is where the real risk sits, and it has nothing to do with whether a trench was dug.

Where a permission carries a condition requiring something to be approved before development begins, carrying out a material operation without that approval is a breach. The courts have held that operations carried out in breach of a condition of that kind are not lawful operations under the permission, so they do not implement it. A developer who digs the foundation trench on the last day of the three years, with an undischarged pre-commencement condition, may find the permission expired anyway.

Not every condition expressed in those terms has that effect. The courts have drawn a distinction between a true condition precedent, going to the heart of the permission, and a condition whose breach does not prevent lawful implementation. The distinction is fact-specific and it has produced a good deal of litigation, which is a reason to discharge the conditions rather than to argue about which kind they are.

Practical sequence, four weeks before the expiry date:

1. List every condition using the words "before development begins", "prior to the commencement of development" or similar, and check each against the discharge applications made.
2. Confirm in writing with the authority that each one has been discharged, and keep the decision notices.
3. Where one is outstanding, do not start. Submit the discharge application and, if time is short, consider a section 73 application or a fresh application rather than an unlawful start.
4. Only then carry out the material operation.

The relationship between discharging conditions and approving details is a separate source of confusion, and it is set out in approval of details or discharge of conditions.

Evidence of the works carried out

Whoever asserts that a permission was implemented has to prove it, and the proof is usually needed years later by a purchaser's solicitor.

Build the evidence at the time. Dated photographs showing the works in context, including a recognisable site feature. A site diary entry naming who carried out the works and when. The contractor's invoice describing the operation. A drawing marking the location of the trench or the road works against the approved plans, so the works can be shown to form part of the permitted scheme. Where a building control initial notice was given, keep it.

A statutory declaration made at the time by the person who carried out the works is worth more than one made six years later from memory, and it costs very little.

Consequences of an unlawful start

If the works relied on were not material operations, or were carried out in breach of a condition precedent, the position is unattractive. The permission expires on its time limit. The works already carried out are unauthorised development. Anything built afterwards is unauthorised and liable to enforcement, subject to the time limits for taking action.

The routes out are a retrospective application under section 73A, a fresh application for the whole scheme, or in a narrow case an application for a lawful development certificate if enough time has passed. None of them preserves the original permission, and a fresh application reopens the policy position, which on a site where the plan has moved on is a real risk. The Planning Statement for that fresh application has to argue the scheme afresh rather than relying on the earlier grant.

Deciding whether a permission is alive

Six questions, in order, and they are the questions a careful solicitor will ask.

What does the permission say about the time limit, in the condition rather than in the covering letter? Was a material operation within section 56(4) carried out, and is it evidenced? Did that operation form part of the development permitted? Was it more than trivial? Were all pre-commencement conditions discharged before it was carried out? And was the Community Infrastructure Levy commencement notice served where required?

One honest uncertainty: the line between a true condition precedent and an ordinary condition is not sharp, and two experienced practitioners can reach different views on the same condition. That is a reason to treat every pre-commencement condition as if it were a condition precedent.

Reform in this area is live. The Levelling-up and Regeneration Act 2023 introduced provisions on commencement notices and development progress reporting, and the position should be verified on legislation.gov.uk and gov.uk at the time of writing rather than assumed. The document requirements for a fresh or amended application are set out across the 66 report types, and the reserved matters position is covered in reserved matters and what cannot be reserved.

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.