Permission in principle: when it is worth using

Permission in principle settles three things and nothing else: the location of the development, the land use and the amount of development. It does not deal with access, appearance, landscaping, layout or scale, and it cannot carry conditions. Everything else waits for the second stage.

That narrowness is the whole point. For a small housing plot where the question that matters is whether the council accepts a house there at all, it is a fast and inexpensive way to get an answer. For a constrained site where the principle depends on assessment work, it is the wrong tool.

What it establishes and what it leaves out

The consent comes in two stages. Permission in principle establishes the principle. Technical details consent deals with the detail, and the two together have the same effect as a planning permission.

The statutory framework sits in the Town and Country Planning Act 1990 as amended by the Housing and Planning Act 2016, with the procedure in the Permission in Principle Order 2017.

The amount of development has to be expressed as a range of dwellings, for example five to seven, rather than as a single figure. Get the range right. It fixes the envelope for the technical details stage, and a range that is too narrow leaves no room for the layout to settle.

No conditions can be attached to a permission in principle. Councils that want to control something have to do it at the technical details stage, which is one reason some authorities are lukewarm about the route.

Who can use it and on what sites

There are two ways a site gets permission in principle. The local authority can enter it in Part 2 of its brownfield land register, which grants the principle without an application. Or the applicant can apply for it directly.

The application route is limited. The development must be housing-led, meaning residential is the predominant use, and the site must be below one hectare with fewer than ten dwellings. Development requiring environmental impact assessment is excluded, as is development affecting a habitats site where an appropriate assessment would be needed.

The thresholds are absolute rather than indicative, and the detail of how they apply is covered in our note on the small site limit. The brownfield register route works differently and can cover larger sites, as our note on brownfield land registers explains.

The application process and publicity

The application itself is short. A location plan with the site edged red, the description of the proposed housing development, the range of dwellings, and the fee, which is charged per 0.1 hectare of site area and should be checked against the current schedule.

No supporting statements are required as a matter of validation, and no drawings of the building are needed, because the building is not being assessed.

The authority publicises the application for at least 14 days by site notice, and the determination period is five weeks rather than the eight weeks that applies to a minor full application. That short timetable is the route's main attraction.

The council is deciding whether the location, use and amount are acceptable in principle, having regard to the development plan and other material considerations. It can refuse, and refusal on a permission in principle application carries a right of appeal in the ordinary way.

Technical details consent

Technical details consent is where the scheme itself is assessed: siting, layout, scale, appearance, access, drainage, ecology, amenity, parking and everything else that a full application covers.

The important constraint on the authority is that it cannot revisit the principle. Having granted permission in principle, it must grant technical details consent unless the details themselves are unacceptable. That is a real protection, and it is what gives the first stage its value to a landowner or a lender.

The application is not a light exercise. It needs the drawings and the supporting evidence that any application of that scale would need, including the biodiversity gain plan route where the gain condition applies, and the fee is broadly comparable to a full application.

Determination is five weeks for non-major development and ten weeks for major schemes coming through the brownfield register route.

The time limits between the two stages

Permission in principle granted on application has effect for three years from the date it comes into effect, and an application for technical details consent has to be made within that period. Entries on a brownfield land register carry a longer period.

Three years is less generous than it sounds on a plot being sold. Land transactions, funding and design all have to fit inside it, and a permission in principle that expires unused leaves the site exactly where it started.

Diarise the expiry at the point of grant, and work backwards from it. If the plot is being marketed, tell buyers the date rather than the duration, because buyers often count from the wrong day.

Where it saves time and where it does not

It saves time where the principle is the only genuine question. An infill plot in a village with no designations, inside the settlement boundary, where the council's position on a single dwelling is the unknown. Five weeks and a modest fee is a reasonable way to find out.

It also has value as a marketing tool. A plot with the principle established sells differently from one without, and the seller has not had to pay for a full design that the buyer will discard.

It does not help where the principle depends on evidence. A site in a conservation area, in flood zone 2 or 3, with protected trees, or adjoining a listed building, raises questions the council cannot answer without assessment, and it will usually refuse rather than grant a principle it cannot test. The same applies where highway access is the central issue, because access is not part of the first stage at all.

It is also poorly suited to anything other than straightforward housing. Mixed use, self-contained annexes with an uncertain use, replacement dwellings with a debatable lawful use, and rural sites relying on a policy exception all need the argument made in full, with supporting documents attached.

Choosing between this and outline permission

Outline permission remains the flexible option. It can cover any scale of development, including major schemes and environmental impact assessment development, it allows some matters to be reserved and others settled, and it can carry conditions that lock in what has been agreed.

Permission in principle is faster at the first stage, lower in cost, and narrower. The trade-off is the absence of conditions and the inability to resolve anything beyond location, use and amount.

A practical way to choose: if you could write the description of development in one line and expect the council to say yes or no without asking for a report, use permission in principle. If the answer depends on what the scheme looks like or how it is accessed, use outline or go straight to a full application. Our comparison of outline permission and permission in principle sets the two side by side.

Follow changes to the small sites regime through the planning law timeline, and enter your postcode on PlanScope to see which reports a plot is likely to need at technical details stage.

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.