Permission in Principle: The Complete Guide
A complete guide to permission in principle - how the two-stage consent route works, what's excluded, current fees and timescales, and when it's the right choice for your site.
PLANNING APPLICATIONS
Andrew Ransome
9/12/20265 min read
Permission in principle has been available since 2018, but it remains one of the least understood routes to planning consent. Many landowners have never heard of it.
It is common to go straight to a full or outline application without considering whether it might be the better fit. That's often a missed opportunity, because for the right site, permission in principle can secure certainty on the fundamentals of a scheme at lower cost and with less upfront technical work than the alternatives.
This guide sets out how the permission in principleroute works, what it can and can't be used for, and where it fits alongside outline planning permission.
What permission in principle actually is
Permission in principle is a two-stage consent route for housing-led development. It separates the principle of development on a site from the technical detail of that development.
Stage 1 — permission in principle. This establishes whether a site is suitable in principle, considering only location, land use and the amount of development proposed.
Stage 2 — technical details consent (TDC). This is where the detailed proposals are assessed: design, access, drainage, ecology, heritage, and everything else that would normally be considered at full application stage.
A full planning permission only exists once both stages have been passed.
The two routes to permission in principle
There are currently two ways a site can obtain permission in principle.
1. Permission in Principle application. A landowner or developer applies to the local planning authority in the normal way, using a permission in principle application form. The LPA (or an Inspector, on appeal) decides whether to grant it.
2. Entry onto Part 2 of a brownfield land register. Local planning authorities are required to maintain a brownfield land register identifying land they consider appropriate for residential development. Sites can be entered onto Part 2 of that register. This triggers an automatic grant of permission in principle, subject to public consultation and statutory requirements being met.
The two routes are not identical in scope. Critically, major development can be granted permission in principle via the brownfield register route, but not by direct application.
What can't get permission in principle
Whichever route is used, certain types of development are excluded.
By a permission in principle application, permission in principle cannot be granted for:
Major development (broadly, 10 or more dwellings, or a site of 1 hectare or more, or non-residential development of 1,000m² or more)
Householder development
Habitats development
Environmental Impact Assessment (EIA) development
Via the brownfield register route, the exclusions are similar but not identical. Major development is permitted through this route, while development on land that isn't previously developed is not.
The habitats development exclusion is worth flagging on its own. If a proposal is likely to have a significant effect on a qualifying European site, e.g. a Special Protection Area or Special Area of Conservation, permission in principle cannot be granted unless an Appropriate Assessment has concluded there will be no adverse effect on the integrity of the site, taking mitigation into account.
In areas with SPA zones of influence, this needs checking early, not discovered at refusal stage.
What stage 1 actually considers
The scope of the permission in principle decision is limited to three matters:
Location — is the site an acceptable location for housing-led development, having regard to the development plan and the NPPF?
Land use — is residential use acceptable here?
Amount of development — expressed as a minimum and maximum number of dwellings, not a fixed figure.
Everything else — design, access details, drainage strategy, ecological mitigation, heritage impact assessment — is deferred to the technical details consent stage.
No conditions can be attached to a grant of permission in principle, and no planning obligations can be secured at this stage either.
This is the feature that makes permission in principle attractive for sites where the principle of development is genuinely the point of contention. For example, a site outside a settlement boundary, or a location where the local planning authority's five-year housing land supply position is in dispute.
Rather than commissioning a full suite of technical reports before knowing whether the principle is even acceptable, an applicant can test the principle first and invest in technical work only once it's established.
Fees and timescales
For a direct application (fees correct at 1 April 2026):
Permission in principle: £531 for each 0.1 hectare of site area (or part thereof)
Technical details consent: treated as a full planning application fee, calculated on the usual basis (number of dwellings, floorspace, and so on)
By comparison, an outline application for the erection of dwellings on a site under 0.5 hectares currently costs £610 for each 0.1 hectare — so the permission in principle route is cheaper at the principle stage, on top of requiring less supporting information.
The local planning authority has 5 weeks from receipt of a valid application to determine a permission in principle application.
If they fail to do so, there's a right of appeal to the Planning Inspectorate for non-determination, exactly as with any other application.
Technical details consent applications carry the same statutory determination periods as full planning applications.
How long permission in principle lasts
Granted by direct application: 3 years, within which a technical details consent application must be determined.
Granted via the brownfield land register: 5 years.
If technical details consent isn't secured within that window, the permission in principle lapses.
If a technical details consent application is refused, the permission in principle itself is unaffected. A fresh technical details consent application can still be made, provided the permission in principle hasn't expired in the meantime.
Permission in principle versus outline planning permission
The comparison comes up constantly, so it's worth setting out here.
Both are two-stage routes that separate principle from detail.
But permission in principle is only available for minor, housing-led development.
outline permission has no such restriction and can be used for major schemes and non-residential development alike.
Permission in principle also requires less supporting information at the first stage, which keeps upfront costs down, and — as set out above — is marginally cheaper in fee terms at that stage.
For a small housing-led scheme where the principle is the live issue, permission in principle is often the more proportionate route.
For anything larger, or anything where technical matters are more central to viability, outline permission remains the better tool.
A practical view
Permission in principle tends to work well for:
Backland and garden sites in urban areas
Sites at the edge of a settlement, outside the defined boundary, particularly where a five-year housing land supply is difficult to demonstrate
Small-scale self-build projects
Limited infilling within the Green Belt, where the principle of acceptability is the main question
It's less well suited to sites where technical constraints are likely to be the deciding factor rather than the principle of development itself. For example, — flood risk, access, heritage, ecology.
In those cases, front-loading that technical evidence through a full application or an outline application with all matters reserved may be more appropriate may, even if it costs more upfront.
Not every local planning authority is equally familiar with the route, given how comparatively rarely it's used.
It isn't unusual to see a permission in principle application assessed as though it were a full or outline application, with reasons for refusal straying into technical detail that has no place at Stage 1. Where that happens, an appeal can bring the assessment back within its proper scope.
Getting the right advice
Permission in principle is a very useful planning tool, but it isn't right for every project. It is worth getting advice before committing to it.
I've advised on a number of permission in principle applications and appeals, for both landowners testing the principle of development and developers structuring a phased route to consent. If you'd like to discuss your site, contact me.
Andrew Ransome MRTPI - Email: andrew@andrewransome.co.uk
About me
Andrew Ransome is a Planning Director and a Chartered Member of the Royal Town Planning Institute (RTPI), with more than two decades of experience in town planning.
He specialises in delivering strategic planning solutions for complex developments across both rural and urban environments, helping clients navigate planning challenges and unlock development opportunities. Connect with Andrew on Linkedin.
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