Using the brownfield land register in a site search
Every English authority publishes a brownfield land register to a set data standard. What Part 2 entry actually grants, and the checks to run before you bid.
Every local planning authority in England has to publish a brownfield land register, and for a developer running a site search it is one of the few datasets where the council has already done the work of saying a site is suitable for housing. The register comes in two parts. Part 1 is a list of previously developed sites the authority considers appropriate for residential development. Part 2 is much shorter, and entry on it grants permission in principle. Knowing which part a site sits in changes what the entry is worth, and a lot of site-finding time is wasted by people who do not check.
The registers are published to a prescribed data standard, which makes them straightforward to pull and compare across authorities.
What each authority must publish
The Town and Country Planning (Brownfield Land Register) Regulations 2017 require every authority to prepare, publish and maintain a register, and to review it at least once a year.
To go on Part 1 a site has to be previously developed land, be at least 0.25 hectares or capable of supporting at least five dwellings, and be considered suitable, available and achievable for residential development. Those three words carry defined meanings in the regulations and in national guidance, and they are the authority's judgement rather than a test the site has passed.
The prescribed data standard means the fields are consistent: site reference, name and address, coordinates, hectares, ownership status, planning status, minimum and maximum net dwellings, and notes. That consistency is what makes the registers usable in bulk, and the national collection on the planning data service aggregates them so you do not have to visit 300 council websites.
Part 1 and Part 2 are not the same thing
Part 1 is information. It tells you the council thinks housing could work here. It confers nothing, grants nothing, and binds nobody. A Part 1 entry is a lead, not a consent.
Part 2 is a decision. Before entering a site in Part 2 the authority has to carry out publicity and consultation, and the entry itself grants permission in principle for residential development of the site.
Most registers have a substantial Part 1 and an empty or near-empty Part 2. Authorities have been cautious about using Part 2, partly because the consultation work is front-loaded and partly because permission in principle does not sit comfortably with how development management teams are set up. So if you find a genuine Part 2 site, it is worth a closer look than the Part 1 entries around it.
What entry on Part 2 actually grants
Permission in principle settles three things and only three: the location, the land use, and the amount of development. Everything else is dealt with later through an application for technical details consent, which is where layout, design, access, drainage, contamination and everything a normal application covers gets resolved.
The consent is time limited. Permission in principle granted by entry in Part 2 lapses if technical details consent is not obtained within the period set by the Permission in Principle Order 2017, which is longer than the period that applies to permission in principle granted on application. Check the current period against the Order before you build a programme around it.
Two practical consequences. First, a Part 2 site removes the argument about whether housing is acceptable here at all, which is the argument that kills most speculative sites. Second, it does not remove any technical constraint, so a Part 2 site in Flood Zone 3 is still a Flood Zone 3 site. The council's own housing land supply and delivery test figures are a separate check worth running at the same time, because they tell you how much appetite the authority has for windfall sites.
Reading the capacity figures
Each entry carries minimum and maximum net dwelling figures. These are the authority's indicative estimate, usually derived from a density assumption applied to the site area rather than from any layout work.
Treat them as a starting point and nothing more. A 0.4 hectare site with a stated maximum of 14 dwellings may support 20 with a different typology, or eight once you have set the trees, the access visibility splay and the drainage attenuation out on a plan.
Where the figures matter is in the permission in principle case, because the amount of development is one of the three things the consent fixes. A Part 2 entry with a maximum of 14 does not let you build 20, and increasing it means a fresh application.
Cross-checking against the plan and the constraints
A register entry tells you what the planning policy team thought. It does not tell you what the development management team, the highway authority or the lead local flood authority will say.
Run these checks before spending money on a shortlisted site.
- The adopted local plan and its policies map, for allocations, designations and settlement boundaries covering the site.
- Flood zones from the planning flood map, plus surface water risk, because brownfield sites are frequently low lying.
- Heritage designations, including whether the site is in a conservation area or contains a non-designated heritage asset such as a former industrial building.
- Contamination history, since previously developed by definition means something was there before.
- Ecology, because open mosaic habitat on previously developed land is a priority habitat and can change a biodiversity net gain baseline sharply. How to read the inventories is covered in our note on habitat inventories and classification data.
- Ownership and access, which the register records only loosely and sometimes not at all.
The contamination point deserves emphasis. On a brownfield site a Phase 1 desk study is not optional diligence, it is the first document, and the outcome shapes both the price and the programme. A contaminated land assessment must be prepared by a suitably qualified and experienced person, and PlanScope's draft is a starting point for that professional rather than a substitute.
Where the data runs out
Registers are only as good as the authority's knowledge and the date of the last review. A register reviewed in December 2024 will not include a site that closed in 2025.
They are also selective. A site the authority considers unsuitable is simply absent, and absence tells you nothing useful, because the judgement may have been made against a policy position that has since changed or on information that was wrong.
And the register says nothing about whether the owner will sell. Available in the regulations means available for development in planning terms, not for sale at a price you would pay.
So the register is a filter, not a pipeline. It is good for finding sites the council has already accepted in principle, and poor as a sole source of leads.
What to do with a shortlisted site
Order the ecological and ground information early, because both have long lead times and both can end a deal. Book a pre-application meeting and take the register entry with you, because it commits the authority to a position it has published.
Then scope the evidence base. On a small brownfield residential site that usually means a desk study, a preliminary ecological appraisal, a drainage strategy, a transport statement and a planning statement, with heritage and arboricultural work where the constraints call for it. You can see how those documents fit together, and draft them to policy structure, on the report types index.
PlanScope provides AI-assisted draft reports for planning applications. Reports should be reviewed before submission. We do not guarantee planning approval. For specialist technical reports, qualified professional input may be required.
Frequently asked questions
What is the difference between Part 1 and Part 2 of a brownfield land register?
Part 1 lists previously developed sites the authority considers suitable, available and achievable for housing. It grants nothing. Part 2 contains sites the authority has decided to grant permission in principle for, after publicity and consultation, and entry on it carries that consent. Most registers have a large Part 1 and a very small Part 2.
What does permission in principle cover?
Location, land use and amount of development, and nothing else. Layout, design, access, drainage, contamination and every other technical matter is dealt with through a later application for technical details consent. A site with permission in principle in a flood zone is still in a flood zone.
What size does a site have to be to go on the register?
Under the 2017 Regulations a site must be previously developed land and either at least 0.25 hectares in area or capable of supporting at least five dwellings. It must also be considered suitable, available and achievable for residential development, which is the authority's own judgement rather than a test the site has passed.
Are the dwelling capacity figures reliable?
They are indicative estimates, usually derived from a density assumption applied to the site area rather than from any layout work. Treat them as a starting point. They matter more on Part 2 sites, because the amount of development is one of the three things permission in principle fixes and exceeding it needs a fresh application.
How current is the data?
Authorities must review their registers at least annually, so an entry can be up to a year old, and in practice some registers lag further. A site that became available after the last review will be absent, and absence from the register tells you nothing about whether the site could work.
Sources and further reading
This article is general guidance about the planning system in England and, where stated, the rest of the UK. It is not legal or professional advice. Check your local planning authority’s validation requirements and take professional advice for your specific site.