UK Planning Constraints Checker – Conservation Area, Listed Building, Article 4, TPO, Flood Zone

Paste in a list of postcodes or coordinates in England and get back a clear yes/no for every main planning constraint at each one: conservation area, listed building, Article 4 direction, Tree Preservation Order, flood zone 2/3, green belt, national park, National Landscape (AONB), SSSI, scheduled monument, World Heritage Site and more. Each row also lists the listed buildings nearby with their grade and distance, a plain-English note on what each constraint means, and a link to the official map.

Everything comes from the government's official planning.data.gov.uk (MHCLG) API, published under the Open Government Licence. No API key, no login, no scraping.

Who uses this

• Property investors, sourcers and buy-to-let landlords – screen a deal list before you view: is it in a conservation area, under an Article 4 HMO direction, or in flood zone 3?
• Estate agents and conveyancers – flag listed status and conservation areas early, before the searches come back.
• Architects, builders and extension firms – know whether permitted development is likely to apply before you quote.
• Tree surgeons – check for conservation areas and protected trees before you start work.
• PropTech and data teams – add constraint columns to a whole portfolio on a schedule.

What you get per location

Column	Example
inConservationArea / conservationAreaNames	true / Bath
inListedBuilding / listedBuildingNames	Is the point inside a mapped listed-building outline
listedBuildingsNearby	Grand Pump Room (grade I, 8 m); King's Bath (grade I, 20 m); …
nearestListedBuildingMetres	8
inArticle4 / article4Names	true / HMO
inTreePreservation, protectedTreesWithinRadius	TPO areas at the point and protected trees nearby
floodZone, inFloodZone2or3	Flood Zone 3, true
inGreenBelt, inNationalPark, inNationalLandscape, inSssi, inScheduledMonument, inWorldHeritageSite, inRegisteredParkAndGarden, inRegisteredBattlefield	yes/no columns with names
Optional extras	ancient woodland, heritage coast, SAC, SPA, Ramsar, national and local nature reserves, brownfield land register, heritage at risk
conservationAreaCoverage, article4Coverage, treePreservationCoverage	Whether the council publishes that layer at all (see below)
whatItMeans	One plain-English line per constraint found
summary	One sentence for the whole location
localAuthority, localPlanningAuthority	Chichester, South Downs National Park LPA
planningDataMapUrl, sourceEntities	Link to the official map and the source records

The "honest blank" – why coverage columns matter

Conservation areas, Article 4 directions and TPOs are published by each council, and not every council has published them yet. Most tools just say "no" when the data is missing. This one checks whether the council (and the national park authority, where there is one) has published each layer at all:

• found – the constraint applies here.
• council publishes this data – none at this point – a real "no".
• not published by council – unknown – "no" here means "we don't know"; ask the council. A matching line is added to coverageWarnings.

If a listed building sits within 15 m but no outline is mapped, you also get a warning to check whether the property itself is listed.

Input

Field	Default	Notes
Locations	BA1 1LZ, 53.9580,-1.0790, GU29 0BP	Postcodes, latitude,longitude strings, or objects like {"latitude": 51.50, "longitude": -0.14, "label": "Site A"}
Listed building radius (m)	50	0–500. Lists nearby listed buildings and protected trees.
Include extra designations	true	Ancient woodland, nature sites, brownfield, heritage at risk.
Include ended designations	false	Include records with an end date.
Max locations	1000	Safety cap per run.

{"locations": ["BA1 1LZ", "53.9580,-1.0790", {"postcode": "GU29 0BP", "label": "Midhurst farm"}], "listedBuildingRadius": 50}

Example output (one record, trimmed)

{
  "input": "53.9580,-1.0790",
  "status": "checked",
  "localAuthority": "York",
  "inConservationArea": true,
  "conservationAreaNames": "Central Historic Core Conservation Area",
  "inArticle4": true,
  "article4Names": "HMO",
  "floodZone": "Flood Zone 3",
  "inFloodZone2or3": true,
  "listedBuildingsWithinRadius": 5,
  "nearestListedBuildingMetres": 18,
  "listedBuildingsNearby": "Merchant Adventurers Hall (grade I, 18 m); Gatehouse To Merchant Adventurers Hall (grade II*, 31 m); …",
  "treePreservationCoverage": "not published by council – unknown",
  "constraintsFound": ["Conservation area", "Article 4 direction", "Flood Zone 3"],
  "whatItMeans": ["Conservation area: Extra controls on demolition, some extensions, cladding and satellite dishes; give the council 6 weeks' notice before most tree work.", "…"],
  "summary": "Found: Conservation area, Article 4 direction, Flood Zone 3. Not published by the council, so 'no' means unknown: Tree Preservation Order area.",
  "planningDataMapUrl": "https://www.planning.data.gov.uk/map/#53.958,-1.079,17z"
}

Full sample rows are in samples/sample_output.json.

Pricing

$0.005 per location checked (pay per event). Invalid inputs, unknown postcodes and locations outside England are returned with a reason and not charged. About 200 locations take under a minute.

Good to know

• England only. planning.data.gov.uk does not cover Wales, Scotland or Northern Ireland; those rows come back as outside-england, free.
• Postcodes are checked at their centre point. A postcode can cover several streets, so for a single property use its coordinates.
• Flood zones are the Environment Agency's planning flood zones (rivers and sea) as published on planning.data.gov.uk – not surface water risk and not an insurance rating.
• Not legal advice and not a substitute for official local authority searches (CON29/LLC1). Data can lag council decisions. Always confirm with the council before buying or building.

FAQ

Does "no" mean there is no constraint? Only when the coverage column says the council publishes that layer. Otherwise treat it as unknown. Can I run it on a schedule? Yes – use Apify Schedules and the Excel/CSV/JSON export or the API. Why are some listed buildings not "on the point"? Historic England publishes most listed buildings as points, not outlines, which is why we also list everything within your chosen radius.

Data sources and licence

• Contains public sector information from planning.data.gov.uk (MHCLG) licensed under the Open Government Licence v3.0. © Crown copyright and database right 2026.
• Postcode locations via postcodes.io: contains OS data © Crown copyright and database right 2026; contains Royal Mail data © Royal Mail copyright and database right 2026; source: Office for National Statistics licensed under the Open Government Licence v3.0.

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