Green Belt Map UK: How to Check Land

Official Green Belt map sources: MHCLG data and council GIS

Green Belt is a planning designation drawn by councils, not a type of land. Our guide explains what Green Belt land is and when you can build on it. This article is only about finding the line.

Four official sources show it. Each has a different job, so use them in this order.

The national data starts with councils. In MHCLG's words, "Local authorities digitise areas of land designated as Green Belt and send the Green Belt boundaries". MHCLG then merges them and checks the quality.

Planning Data gives the same boundaries a map and a postcode search. It also says the data "provides a snapshot in time". It will not show boundary changes made since the March returns.

That gap matters. Seven councils adopted plans that changed their Green Belt in 2025-26 alone. Boundaries change through the local plan, under NPPF policy GB3, so the council's adopted policies map is the one to confirm.

Have the site's postcode ready, then follow the steps below.

Green Belt postcode check, step by step

The government's postcode route is the Planning Data map. It searches across England. Follow these steps for each site you look at.

1. Open the map. Go to planning.data.gov.uk and open the map view of the Green belt dataset.
2. Search the postcode. Choose "Postcode" as the search method, type it in and press "Find". You can search by UPRN instead, a reference for a single property.
3. Find the plot, not the postcode. A postcode can cover several properties. Zoom in until you see the site's own edges against the shaded area.
4. Check the edges. If the line crosses the site, note which part sits inside.
5. Note the date. The data comes from council returns made each March. Anything adopted since will not show.
6. Confirm with the council. Open the adopted local plan policies map on the council's website. If the two differ, ask the council's planning policy team which is current.

The same map has other planning layers, such as conservation areas and flood risk zones. Planning Data warns that its data "may be incomplete and not yet cover all of England". So a blank layer is not proof that a constraint is absent. Note every layer that touches the site; you will need the list for the checks further down.

London Green Belt map and boundary

London has the smallest Green Belt area of the nine English regions, at 34,780 hectares. Yet it has the highest share of any region, at 22.1% of its land.

The best London Green Belt map is the GLA Planning DataMap. It groups London-wide layers under "Protection", "Good Growth" and "Context". Check its layer list for Green Belt.

London also has Metropolitan Open Land, or MOL. This is strategic open land inside the built-up city, separate from the Green Belt. Check the layer list for it too. A site can miss the Green Belt and still sit on MOL.

The DataMap also carries "local plan policy layers from each London Planning Authority" under Borough Layers. Click the map to find sites within layers at that point. That puts the borough's own designations beside the London-wide ones.

For a site just outside London, use the Planning Data map and the neighbouring council's policies map.

What the Green Belt map does not tell you

A Green Belt map answers one question: is the land designated? It does not tell you whether you can build, or what the site is worth.

Grey belt. No official map shows it. The latest statistics give no estimate of grey belt land. Councils identify it in Green Belt assessments, or weigh the evidence site by site where no assessment covers it. See our guide to grey belt land and its tests.

Previously developed land. The map does not say whether a site is brownfield. Land last used for farm or forestry buildings is not previously developed. Our guide to greenfield and brownfield sites sets out the definition.

Article 4 and permitted development. Green Belt is not article 2(3) land, so it does not remove permitted development rights by itself. An Article 4 direction can. Planning Data holds 7,649 Article 4 areas from 120 providers, but warns that the data may be incomplete.

Even a clear map leaves the planning route open. Inside the Green Belt, building is inappropriate unless it fits an NPPF exception or very special circumstances apply.

Our free feasibility checklist below puts these checks in order, with planning, constraints and build cost.

Next step: test the site before you offer

The map tells you where the line runs. The value of the site depends on the planning route, the other constraints and the cost to build. Price all three before you agree a figure with the seller.

We test every deal before an offer: the planning chance, the build cost from our own team, and a residual appraisal. We did that on the Allitsen Road study, at £6.0M GDV.

Rob Barton, our Development Director, took 10,000+ homes through planning in his previous housebuilding roles. For the purchase itself, read our guide to buying land with or without planning permission.

Found a plot on or near the line? Send us the address and ask for a free first view. A director reads the map, the constraints and the route before you commit.