Time limits for implementation and a material start

A full planning permission in England normally has to be begun within three years of the date it was granted, under section 91 of the Town and Country Planning Act 1990. Outline permissions work differently: reserved matters must be applied for within three years, and the development begun within two years of the final approval of reserved matters, under section 92. Beginning development means carrying out a material operation as defined in section 56(4). Dig a trench for a foundation, and the permission is implemented for the rest of time.

What makes this fraught is the interaction with conditions. A start that breaches a pre-commencement condition may not count at all.

The standard time limit and the variations on it

Section 91 imposes a three year limit unless the permission itself specifies a different period. Authorities can and do impose shorter periods where there is a reason, and longer ones occasionally where a phased scheme justifies it.

Check the decision notice rather than assuming. The time limit appears as condition 1 on almost every notice, and its wording controls.

A permission granted under section 73 to vary a condition creates a new permission with its own decision date, but the courts have held that it cannot extend the original time limit for implementation beyond what the original permission allowed. The practical consequence is that varying a condition in year three does not buy you three fresh years.

What counts as beginning development

Section 56(4) lists the operations that amount to a material operation:

• any work of construction in the course of the erection of a building
• any work of demolition of a building
• the digging of a trench which is to contain the foundations, or part of the foundations, of a building
• the laying of any underground main or pipe to the foundation trench, or to a trench for such a main or pipe
• any operation in the course of laying out or constructing a road or part of a road
• any change in the use of any land which constitutes material development

The threshold is low. Case law has accepted a short section of foundation trench and the pegging out and partial construction of an access road. What it will not accept is work that is colourable, meaning work done purely to create the appearance of a start with no genuine intention of carrying out the development.

Site clearance, fencing, tree removal and the erection of a site hut are not on the list. They are common preparatory works and they do not implement anything.

Conditions that must be discharged first

A pre-commencement condition is one worded so that no development may begin until the matter is approved. Where development starts without the approval, the start is in breach, and the long-standing authority is that a breach of a condition going to the heart of the permission means the works are not carried out under the permission at all.

Not every pre-commencement condition has that effect. The test the courts apply looks at whether the condition goes to the heart of the permission, and conditions about materials or landscaping have generally been treated differently from conditions requiring, for example, a contamination remediation strategy or an archaeological written scheme of investigation before any ground disturbance.

Since the Neighbourhood Planning Act 2017 an authority cannot impose a pre-commencement condition without the applicant's written agreement, subject to exceptions. That has reduced their number without removing them.

The practical rule: list every condition on the notice, mark the pre-commencement ones, and discharge all of them before a spade goes in. Where approval is outstanding and the deadline is close, a partial discharge application plus a written agreement with the case officer is worth more than hoping. The companion piece on what must be submitted before work starts on site sets out the usual list.

Evidence that a start was lawful

Nobody from the council attends to witness a trench being dug. The burden of proving implementation falls on whoever asserts it, often years later when a buyer's solicitor asks.

Assemble the evidence at the time:

1. Dated and geolocated photographs of the operation, showing recognisable site features and the work itself.
2. The contractor's invoice and daywork sheets naming the operation and the date.
3. A written statement from the person who carried out the work.
4. A plan marking exactly where on the site the operation took place, cross-referenced to the approved drawings.
5. Copies of every condition discharge approval issued before the date of the start.

Where the stakes are high, apply for a Lawful Development Certificate under section 191 confirming that the development has been begun and may lawfully be completed. That is the only formal route to certainty, and the fee is small compared with the value of a permission.

Keeping a permission alive after a start

Once a material operation has been carried out lawfully, section 91 is satisfied permanently. There is no further time limit on completion unless the authority serves a completion notice under section 94, which requires confirmation by the Secretary of State and is rarely used.

A lawfully begun permission can therefore sit part-built for many years. That does not make it comfortable. Conditions continue to apply, and an authority can take enforcement action against a breach of condition during the 10 year period for a breach of condition under the enforcement regime as amended by the Levelling-up and Regeneration Act 2023. Check the commencement position for the enforcement time limit changes, because the transitional provisions matter for breaches that began earlier.

Partially implemented permissions also complicate section 73 applications later. Varying a condition on a permission that has already been partly built out requires care about what the new permission can authorise.

When a permission has lapsed

If the three years passed with no material operation, the permission is gone. There is no extension mechanism; the temporary power to apply to extend expired in 2012.

The options are a fresh application on the same terms, which is the usual route and attracts the full fee, or, where the scheme has changed little and the policy position is unchanged, a fresh application presented as a renewal in substance with the previous approval as a strong material consideration. Policy will have moved. Biodiversity net gain alone means that a scheme permitted before February 2024 and re-applied for now needs a metric and a gain plan it never previously required.

That single change has caught a number of lapsed residential consents. Budget for it.

Recording the start properly

Write to the authority before you begin, giving the date you intend to carry out the material operation and confirming which conditions have been discharged. Many councils have a commencement notification form; several require one by condition, and under the Community Infrastructure Levy Regulations 2010 a commencement notice is required before starting on a CIL-liable development, with the loss of any exemption and a surcharge if it is missed.

That CIL notice is the one most often forgotten by self-builders, and the self-build exemption is lost if the commencement notice is not served before work begins. The sequence is: claim the exemption, receive the acknowledgement, serve the commencement notice, then start.

Set the file up so the evidence exists without anyone having to remember. A Planning Statement drafted for the original application will not help you here, but a short implementation file of photographs, invoices and discharge decisions will.

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This is general guidance rather than 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.