6 government websites every property developer should bookmark
The essential free government data websites for checking planning constraints, environmental designations, flood risk and heritage status on development sites in England.
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.
All six sites below are free, and each is worth bookmarking. If you screen many sites and want one place to start, check a site free shows your council, whether the site is in a conservation area, and a basic flood check, with no signup.
If you work in property development, the first question for any site is: what are the constraints? The answer is spread across several government websites, each with its own data, search tools and quirks.
Here are the six government websites to know, what each gives you, and when to use it. This guide covers England. Wales and Scotland have their own publishers.
1. planning.data.gov.uk
planning.data.gov.uk, the national platform for open planning and housing data in England.
Run by: Ministry of Housing, Communities and Local Government (MHCLG)
What you get: conservation areas, green belt boundaries, tree preservation orders, Article 4 directions, brownfield land registers, local authority boundaries, and a catalogue of more than 200 planning datasets.
Why it matters: this is the national platform for standardised planning data. Local authorities publish their constraint data here, so you can search across council boundaries without visiting each council's website.
Best for: checking policy-related constraints such as conservation areas, green belt and Article 4 directions at the early feasibility stage.
Tip: coverage varies by council, 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 the map does not prove there is no constraint. Ask the council.
2. Historic England: National Heritage List for England
Run by: Historic England
What you get: every listed building (Grade I, II* and II), scheduled monument, registered park and garden, registered battlefield and World Heritage Site in England.
Why it matters: heritage designations are among the most important constraints. A listed building cannot be altered without consent. A scheduled monument cannot be disturbed without separate government consent. Development near either gets closer scrutiny.
Best for: confirming the exact grade and extent of heritage assets on or near a site. The detailed list descriptions are essential reading for any heritage statement.
3. Environment Agency: Flood Map for Planning
The Flood Map for Planning, a free GOV.UK service for checking flood zone classifications on any site.
Run by: Environment Agency
What you get: Flood Zone 2 (medium probability) and Flood Zone 3 (high probability) boundaries, and a Flood Zones plus climate change layer showing how those zones may expand under climate allowances. The map was rebuilt on 25 March 2025.
Why it matters: the flood zone decides whether you need a flood risk assessment and whether the Sequential Test applies. Sites in Flood Zone 3 are the hardest to develop. Homes there are "more vulnerable" development and need to pass the Exception Test as well.
Best for: early go or no-go decisions on sites near rivers or the coast. If a site is entirely in Flood Zone 3, or falls inside the climate change extent, the viability of housing is open to question from the start.
4. Natural England: MAGIC map
The MAGIC map, an interactive viewer showing SSSIs, National Landscapes (AONBs), ancient woodland and other environmental designations across England.
Run by: Natural England and Defra
What you get: SSSIs, National Landscapes (formerly AONBs), ancient woodland, Special Areas of Conservation, Special Protection Areas, Ramsar sites, National Nature Reserves, priority habitats and more.
Why it matters: ecological and landscape constraints can decide whether a scheme works. Development affecting a SSSI needs Natural England's input, and national policy supports it only where it causes no adverse effect or the benefits clearly outweigh the harm. Ancient woodland is effectively irreplaceable, and development that would cause its loss or deterioration should be refused unless there are wholly exceptional reasons.
Best for: screening for ecological problems before you commission a full ecological survey. MAGIC also holds agricultural land classification data, which helps on sites at the edge of settlements.
5. Mining Remediation Authority: interactive map viewer
Run by: the Mining Remediation Authority (formerly the Coal Authority)
What you get: development high risk areas for coal mining, mine entries, shallow coal workings, geological faults and past mining activity.
Why it matters: in coalfield areas, a Coal Mining Risk Assessment is needed to support a planning application. Sites over mine entries or shallow workings may need stabilisation that affects project costs significantly.
Best for: early cost checks on sites in coalfield regions. If the viewer shows a development high risk area, allow for a mining report and possible ground stabilisation.
6. GOV.UK: find your local council
Run by: GOV.UK
What you get: confirmation of which council covers your site, and a link to that council's website, where its local plan, policies map and planning department contacts are published. In two-tier areas, planning is normally handled by the district or borough council.
Why it matters: planning policy is set locally. The local plan, neighbourhood plans and supplementary planning documents all vary by authority. Knowing which authority covers the site is the starting point for understanding the policy framework that will decide your application.
Best for: confirming jurisdiction, especially near council boundaries, and getting to the right council for its up-to-date local plan and policies map.
Checking them in one place
Checking each of these websites works, but it is slow. For a typical site appraisal you might spend 30 minutes to an hour pulling together results from four or five sources.
Check a site free shows your council, whether the site is in a conservation area, and a basic flood check, with no signup. The site report (£9.99, one-off) adds heritage, green belt, trees, Article 4 directions, 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. See a sample report before you buy.
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. It is not an official local authority search or professional advice.
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.