Previously developed land: what counts as brownfield

The previously developed land definition sits in the glossary of the National Planning Policy Framework, and it is shorter than the arguments it generates. Land is previously developed if it is or was occupied by a permanent structure, including the curtilage of the developed land and any associated fixed surface infrastructure. Four categories are then carved out, and those exclusions decide most disputes.

Getting the label right matters because national policy treats brownfield land favourably, particularly for housing within settlements and for certain forms of development in the Green Belt. An applicant who claims the status without the evidence to support it undermines the rest of the case.

The definition and the four exclusions

The Framework's glossary excludes four categories from previously developed land.

Land that is or was last occupied by agricultural or forestry buildings. Land developed for minerals extraction or waste disposal by landfill where provision for restoration has been made through development management procedures. Land in built up areas such as residential gardens, parks, recreation grounds and allotments. And land that was previously developed but where the remains of the permanent structure or fixed surface structure have blended into the landscape.

The glossary also adds a qualification inside the definition itself: although the curtilage is included, it should not be assumed that the whole of the curtilage should be developed.

Cite the edition whenever you quote this. The Framework was re-issued in December 2024 and again on 17 August 2026, and the current edition organises policy by code rather than by paragraph number. The glossary wording has been stable, but verify it against the published document before you put it in a planning statement, and refer to the edition you used.

Agricultural and forestry buildings

A steel portal frame barn on a working farm is not previously developed land. Neither is a redundant Dutch barn, a grain store or a forestry shed, because the exclusion turns on the last occupier rather than on the current condition.

That surprises people who assume that any structure counts. It also explains why converting agricultural buildings runs through its own permitted development route under Part 3 of the GPDO rather than through brownfield policy.

The word to test is "last occupied". A former agricultural building that has been in lawful commercial use for a decade, evidenced by tenancy agreements and business rates, may no longer be last occupied by agricultural use. That is an evidential argument, and it needs the planning history to support it.

Residential gardens and the built up area point

The garden exclusion was introduced to stop back garden development being treated as brownfield. It is drafted narrowly, and the qualifier does a lot of work: it excludes land in built up areas such as residential gardens, parks, recreation grounds and allotments.

A garden in an isolated rural location is not obviously within a built up area, so the exclusion may not apply to it. That does not make development acceptable, because the countryside policies still bite and the site may be unsustainable on ordinary tests. What it does mean is that an officer report which dismisses a rural garden site as excluded by definition may have gone a step too far.

Parks, recreation grounds and allotments are excluded whether or not they contain pavilions and changing rooms. The structure does not convert the open space.

Hardstanding, yards and former uses

Fixed surface infrastructure is inside the definition, so a concrete yard, a haulage apron, a former car park and the hardstanding around a demolished building all count, provided they are associated with the developed land.

The practical test on a rural or semi rural site has three parts. Was there a permanent structure, and when. What was the extent of the curtilage associated with it. Have the remains blended into the landscape.

The third question is where most cases turn. A scatter of concrete bases under bramble is a blended remnant. A hardstanding still visible on aerial imagery, still used for parking and still bounded by a wall is not.

Build the evidence before the argument. Historic Ordnance Survey extracts, sequential aerial photography, the planning history including any consents for the former use, business rates records, and a measured survey showing the extent of surviving hardstanding. Present it as a chronology, then state the conclusion. Where the site carried an industrial or commercial use, a contaminated land assessment will normally be needed in any event, and the Phase 1 desk study covers much of the same documentary ground. That report should be prepared in accordance with BS 10175 by suitably qualified and experienced persons.

Brownfield land registers and permission in principle

Every local planning authority in England keeps a brownfield land register under the Town and Country Planning (Brownfield Land Register) Regulations 2017. Part 1 lists previously developed sites the authority considers suitable, available and achievable for residential development. Part 2 contains the sites the authority has chosen to enter after publicity and consultation.

Entry in Part 2 grants permission in principle for housing led development. That establishes the location, the land use and the amount of development, and the applicant then submits a technical details consent application to settle everything else.

Two practical points follow. Registers are reviewed annually, so a site that is not on one can be promoted for inclusion. And a Part 1 entry carries no consent at all, which is a distinction worth checking before anyone pays a premium for land described in an agent's particulars as being on the register.

Registers also feed the housing land supply picture, which is why the windfall allowance argument often draws on register data.

Arguing the point on a rural or Green Belt site

In the Green Belt the previously developed land question can be decisive, because national policy treats limited infilling and the redevelopment of previously developed land differently from other forms of development. Policy on Green Belt development, including the grey belt concept introduced in the December 2024 Framework, has been revised more than once, so check the current edition rather than quoting a paragraph number from an older copy.

Where the status is contested, the structure of a good argument is the same each time.

1. Establish the former use and the date it ceased, with documentary evidence.
2. Define the curtilage associated with the permanent structure, and map it.
3. Address each of the four exclusions expressly, including the ones that plainly do not apply.
4. Deal with blending into the landscape with photographs taken in both summer and winter.
5. Set out what proportion of the curtilage you propose to develop, and why that is appropriate.

Point five is the one applicants skip. The Framework says the whole curtilage should not be assumed developable, so a scheme that covers every square metre of a former depot invites the officer to apply that qualification against you.

Where the argument fails, it usually fails on evidence rather than on interpretation. Decision makers apply the development plan first, and our note on what counts as the development plan explains why local policy wording can narrow the national definition in practice.

This is general guidance, not legal advice. Check the position with your local planning authority or a qualified professional before relying on it.

You can draft the planning statement and technical reports for a brownfield scheme from the full report index and send the specialist ones for professional review. PlanScope provides AI-assisted draft reports for planning applications. Reports should be reviewed before submission. We do not guarantee planning approval.