Completion notices and unfinished development explained

A completion notice is a local planning authority's formal warning that a planning permission will cease to have effect on a stated date unless the development is finished before it. The power sits in section 94 of the Town and Country Planning Act 1990, the notice must allow at least twelve months, and under the long-standing procedure it only takes effect once the Secretary of State confirms it. For anyone holding a part-built scheme, the risk is narrower than the name suggests. The notice does not oblige a developer to finish anything, and it cannot take away what is already lawfully built.

That gap between what the power sounds like and what it does explains why most planning officers have never served one.

What the notice does to a permission

Section 94 applies where development has been begun within the time limit attached to the permission but has not been completed. The authority may serve a notice stating that the permission will cease to have effect at the end of a further period specified in the notice.

The effect is prospective only. Work already carried out under the permission stays authorised, so a half-finished block does not become unlawful development the day the notice bites. What disappears is the authority to carry out the rest. Anything still unbuilt on the expiry date needs a fresh planning permission before it can be built.

That is the whole mechanism. A council cannot use section 94 to force a contractor back on site, cannot recover its costs through it, and cannot use it to require demolition of what is standing.

When an authority can serve one

The trigger is a stalled build on a permission that has already been implemented. The authority must form the view that the development will not be completed within a reasonable period. That judgement is theirs, and it is the point most often argued over, because "reasonable" is not defined by the section.

In practice officers look at how long the site has been idle, whether the developer has a funding route, whether the remaining works are a fortnight of snagging or two further storeys, and what the unfinished state is doing to the area. A site that stopped six months ago because a main contractor went into administration is a different proposition from a shell that has stood open to the weather for nine years.

The notice must be served on the owner and the occupier of the land, and may be served on any other person with an interest in it. Lenders with a charge over the site are usually among them, which is one reason the arrival of a notice tends to concentrate minds faster than the notice itself ever would.

The minimum period and the confirmation stage

The period stated in the notice cannot be less than twelve months from the date the notice takes effect. Under sections 94 and 95 the notice has no effect at all unless and until the Secretary of State confirms it, and on confirmation a longer period may be substituted.

Before confirming, the Secretary of State must give the owner, the occupier and the authority the opportunity to appear before and be heard by an appointed person. That is a hearing or an inquiry, with the preparation and delay that implies. The authority may also withdraw the notice at any time before the stated period expires, and often does, because the notice has usually achieved its real purpose by then.

Add those stages together and a council that serves a notice in the spring is unlikely to see the permission actually lapse before the second winter after that, at the earliest.

The unbuilt part and what replaces it

Once a permission has ceased to have effect for the unbuilt element, the developer is back in the queue with everyone else. A fresh application is assessed against the development plan and national policy as they stand at that date, not as they stood when the original permission was granted.

For a scheme consented several years earlier, that can mean a materially different set of requirements: mandatory biodiversity net gain under the Environment Act 2021, a current Energy Statement reflecting the Part L uplift, updated Environment Agency climate change allowances in the drainage design, and whatever the adopted local plan now says about density and affordable housing. Some of those obligations will improve the scheme. Others will make what is left uneconomic to build, which is exactly the outcome a council does not want when it is staring at an unfinished frame.

Illustrative example: a permission for eight houses is implemented, four are built and sold, and the remaining four plots sit on hardcore for five years. A completion notice, if confirmed, would leave the four built houses untouched and lawful, and would require a new application for the other four. On that fresh application the affordable housing position, the biodiversity gain plan and the drainage strategy would all be reassessed. This example is illustrative and not drawn from a decided case.

Why so few are served

The procedure is slow, the minimum period is long, and the remedy is weak. A confirmed notice removes a permission the developer is not using anyway, and in doing so it removes the one thing that would let them finish without starting again if funding returned.

So authorities reach for other tools. Section 215 of the same Act allows a notice requiring steps to remedy the condition of land that adversely affects the amenity of the area, which is aimed squarely at the untidy hoarding and the weed-grown plot. Sections 77 to 79 of the Building Act 1984 deal with dangerous and with ruinous or dilapidated buildings. Neither touches the permission, and both act faster on the thing residents actually complain about.

The Levelling-up and Regeneration Act 2023 contains provisions that would change the completion notice procedure, including the role of the Secretary of State in confirming notices. Commencement of individual provisions in that Act has been staged, so check the current commencement position on legislation.gov.uk rather than assuming the reformed procedure is in force.

Responding to a notice on your site

Deal with it as a negotiation with a statutory backstop, because that is what it is.

1. Check the notice names the right land, the right permission and a period of at least twelve months, and note the date it was served.
2. Establish what "completion" means for this permission. Is the authority pointing at outstanding conditions, unbuilt plots, or an unfinished elevation? The answer changes the cost of compliance.
3. Write to the case officer with a programme. A dated build programme with a funding position behind it is the single most effective response, and it is usually why notices get withdrawn.
4. If confirmation is pursued, take the opportunity to be heard. The test is whether the development will be completed within a reasonable period, and evidence of a contractor appointment or a signed facility speaks to that directly.
5. Price the alternative. Work out what a fresh application for the unbuilt element would cost and what current policy would add to it, then compare that with finishing now.

Most disputes end at step three. But the arithmetic at step five is what tells you how hard to fight.

If a fresh application is the likely route, the supporting documents are the same ones any application of that scale needs. A Planning Statement setting out the planning history and why the site stalled carries real weight, and the wider bundle depends on what the site triggers. The full set of report types is listed at all 66 report types by category. Related procedural ground is covered in our notes on holding directions and on non-determination and the deemed refusal appeal.

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.