7 free open data sources to check planning constraints in England
A guide to the best free government open data sources for checking planning constraints on any site in England, what each one covers and where each one has gaps.
Checking a specific site?
Check a site free: your council, whether you are in a conservation area, and a basic flood check. The £9.99 site report covers everything else we can check.
Postcode, address or grid reference. England, Wales and Scotland. Free check, then the site report is £9.99, one-off.
Every source below is free, and we recommend you use them. If you would rather check one site in one place, check a site free shows your council, whether you are in a conservation area, and a basic flood check, with no signup.
Checking planning constraints can mean working through several government websites, each with its own map and search quirks. Open data makes the information free to access, if you know where to look.
Here are the seven key open data sources for planning constraints in England, what each covers, and how to use them. Wales and Scotland have their own publishers, which this guide does not cover.
1. Planning Data (planning.data.gov.uk)
The planning.data.gov.uk platform provides open access to planning and housing datasets across England.
What it covers: conservation areas, green belt, tree preservation orders, Article 4 directions, local authority boundaries, brownfield registers and dozens of other local planning datasets.
Who runs it: the Ministry of Housing, Communities and Local Government (MHCLG).
This is the most comprehensive open data platform for planning constraints. Local planning authorities publish their spatial data here in a standard format, so you can query constraints across council boundaries.
The data is available through a public API and an interactive map, both free to use.
Limitation: coverage depends on councils publishing their data, and the platform says its data "may be incomplete and not yet cover all of England". On 19 October 2026 the conservation area dataset had 157 data providers, the Article 4 direction dataset 118 and the tree preservation order dataset 75. A blank on this map does not prove there is no constraint, so ask the council.
2. Historic England: National Heritage List
What it covers: listed buildings (Grade I, II* and II), scheduled monuments, registered parks and gardens, registered battlefields and World Heritage Sites.
Who runs it: Historic England.
The National Heritage List for England is the definitive source for heritage designations. You can search by address, map area or list entry number. Each record describes why the asset is protected and where it is.
Heritage constraints are among the most important for development, and altering a listed building without consent is a criminal offence.
3. Environment Agency: Flood Map for Planning
The Environment Agency's Flood Map for Planning, a free GOV.UK service for checking flood zone classifications.
What it covers: Flood Zone 2 (medium probability), Flood Zone 3 (high probability), and Flood Zones plus climate change, a single layer showing how Zones 2 and 3 may expand under climate allowances. The map was rebuilt on 25 March 2025.
Who runs it: the Environment Agency.
Flood zone data matters for any site near a river, the coast or an area with a history of flooding. If a site is in Flood Zone 2 or 3, you will need a flood risk assessment and may need to pass the Sequential Test, which asks whether the development could go on a lower-risk site. The Sequential Test does not apply to householder development.
The flood map is available as a web viewer and as downloadable spatial data.
4. Natural England: MAGIC map
MAGIC (Multi-Agency Geographic Information for the Countryside) shows environmental designations including SSSIs, National Landscapes (AONBs) and ancient woodland.
What it covers: Sites of Special Scientific Interest (SSSIs), National Landscapes (formerly Areas of Outstanding Natural Beauty, AONBs), ancient woodland, Special Areas of Conservation (SACs), Special Protection Areas (SPAs), Ramsar sites and National Nature Reserves.
Who runs it: Natural England and Defra.
MAGIC is a web-based mapping tool that brings together environmental data from across government. It is the main source for ecological and landscape designations.
For development near SSSIs or ancient woodland, you will often need an ecological impact assessment.
5. Ordnance Survey: open data products
What it covers: boundary lines (administrative, parliamentary, electoral), terrain data, road networks and place names.
Who runs it: Ordnance Survey.
OS open data is not a direct constraint source, but it gives essential context. Knowing which local authority, parish and ward a site falls in tells you which local plan policies apply and which planning department will determine your application.
OS open data products are free under the Open Government Licence.
6. Mining Remediation Authority: interactive map viewer
What it covers: development high risk areas, coal mining features, mine entries, shallow coal workings, and past and current mining activity.
Who runs it: the Mining Remediation Authority (formerly the Coal Authority).
If a site is in a development high risk area for coal mining, a Coal Mining Risk Assessment is needed to support a planning application. This is relevant across much of central and northern England, as well as South Wales and parts of Scotland.
The interactive viewer is free to use. Formal reports for individual properties are available for a fee.
7. Land Registry: Price Paid Data and INSPIRE Index Polygons
What it covers: property transaction history, and the indicative position of freehold registered titles (boundary polygons).
Who runs it: HM Land Registry.
Land Registry open data can help you understand site boundaries and ownership patterns. The INSPIRE Index Polygons dataset shows the indicative position of freehold registered property in England and Wales. Leasehold titles are excluded, and HM Land Registry is explicit that the legal extent of a registered title cannot be established from these polygons.
This does not reveal planning constraints directly, but an indication of where titles sit can help you think about which constraints affect which parts of a site. For the precise legal boundary you need the title plan itself.
Checking them in one place
Each of these sources has its own search interface, map viewer and data format. Checking all of them for one site can take an hour or more, and a blank on any of them does not prove there is no constraint.
Check a site free shows your council, whether you are in a conservation area, and a basic flood check, with no signup. The site report (£9.99, one-off) adds listed buildings, Article 4 directions, trees, green belt, SSSIs and more, with the source for each, for everything we can check within 500 m of your pin, for 30 days. The report link never expires. We show what we found, what came back clear, and where a source couldn't be checked. Some councils don't publish every dataset, so ask the council where it matters.
The government sources above stay free whichever you choose.
Screen a site, see every gap, and send the client a sourced report.
Check a site free, then use the site report (£9.99, one-off) for a sourced summary you can pass on. Pro adds unlimited sites, saved work, monitoring and exports.
We show what we found, what came back clear, and where a source couldn’t be checked. Some councils don’t publish every dataset, so ask the council where it matters. Planning Constraints is a screening tool, not an official local authority search or professional advice.