UK Conservation Areas Data — 9,800+ Designated Areas via API
Query any UK address or coordinate against the complete Historic England conservation areas dataset. Returns polygon boundaries, designation dates, and planning authority metadata — all in a single API call.
What the dataset covers
9,800+ designated areas
Every conservation area designated under the Planning (Listed Buildings and Conservation Areas) Act 1990, sourced from Historic England's open data register and updated as boundaries change.
GeoJSON polygon boundaries
Precise polygon geometries for each area, enabling point-in-polygon lookups. Pass a UPRN, postcode, or lat/lng and receive an immediate in-area determination with boundary data for map overlays.
Designation metadata
Area name, designation date, local planning authority, and Historic England reference. Useful for understanding the age and administrative context of the designation.
Planning context flags
Article 4 direction indicators where applicable, enabling automated flags for properties with the most restrictive development controls within a conservation area.
Sample API response
{
"uprn": "100023336956",
"address": "14 Victoria Road, Bath BA1 3EH",
"in_conservation_area": true,
"conservation_area": {
"name": "Bath City Centre",
"designation_date": "1969-03-21",
"local_authority": "Bath and North East Somerset",
"historic_england_ref": "CA-BAS-001",
"article_4_direction": true,
"boundary": {
"type": "Polygon",
"coordinates": [[[...]]
]
}
}
}Pass any UPRN or coordinate. The API checks the point against all 9,800+ polygon boundaries and returns the matching area — or in_conservation_area: false with an empty object.
Why conservation area data matters
Planning restrictions
Properties inside a conservation area cannot be extended, reclad, or altered under permitted development in the same way as unrestricted properties. Conservation area consent is required for most demolition. Surfacing front gardens with impermeable materials is also restricted. Identifying conservation area status early avoids costly planning surprises.
Property valuation
Conservation area status is a material consideration in property valuation. It can add or reduce value depending on the nature of proposed works. Surveyors, lenders, and estate agents all benefit from knowing in-area status before preparing reports or valuations.
Conveyancing & due diligence
Solicitors routinely check conservation area status as part of the local authority search process. Automating this check via API removes a manual step and ensures consistency across high volumes of transactions. The data covers all 333 planning authority areas in England.
Query any address against 9,800+ conservation areas
Point-in-polygon matching with polygon boundary data. Free tier includes 100 calls per month — no card required.
Get a free API key →Data source & coverage
The dataset is sourced from Historic England's Conservation Area Boundary data, published under the Open Government Licence. This is the definitive national register of designated conservation areas in England.
Local planning authorities are responsible for designating conservation areas. Historic England compiles the national picture by aggregating data from all 333 planning authorities. The dataset is updated when local authorities notify Historic England of new designations, extensions, or boundary changes.
Coverage is England only. Conservation areas in Wales are administered by Cadw and form a separate dataset; Scotland is administered by Historic Environment Scotland. The API currently returns data for England.
Homedata matches each conservation area polygon to Ordnance Survey AddressBase UPRNs, enabling per-property lookups without requiring the caller to handle spatial queries directly.
Who uses conservation area data
Estate agents & portals
Add conservation area flags to property listings. Buyers searching for period homes often specifically seek conservation area properties — and vice versa for those planning extensions.
Surveyors & valuers
Automate conservation area checks in survey reports. The API integrates with report-generation tools to pull in-area status alongside listed building, flood risk, and planning history data.
Conveyancers & solicitors
Pre-populate conservation area status in conveyancing searches. Reduce reliance on local authority turnaround times for searches where the information is already available programmatically.
PropTech developers
Embed conservation area map overlays in property intelligence tools. The GeoJSON polygon boundary supports Leaflet, Mapbox, and Google Maps integrations with minimal transformation.
Pricing
Free
£0
100 calls/mo
Starter
£49
2,000 calls/mo
Growth
£149
10,000 calls/mo
Pro
£349
50,000 calls/mo
Start querying conservation area data today
Join thousands of property professionals using Homedata to automate planning constraint checks. Free tier, no card required.
Get a free API key →FAQ
What is a conservation area in England?
A conservation area is a designated area of special architectural or historic interest under the Planning (Listed Buildings and Conservation Areas) Act 1990. Local planning authorities designate them and must balance development with preserving character. There are approximately 9,800 in England.
How does conservation area status affect planning permission?
Permitted development rights are more restricted inside conservation areas. Changes to external appearance, extensions beyond certain sizes, and the demolition of unlisted buildings all require planning permission rather than falling under permitted development. Article 4 directions can restrict even more works within specific areas.
How current is the data?
The dataset is updated monthly from the Historic England open data feed. New designations and boundary changes submitted by local authorities are reflected in the next scheduled refresh. For the most time-critical queries (e.g. same-day conveyancing searches), we recommend also running a local authority search as the definitive legal source.
Can I retrieve all conservation areas within a radius?
Yes. The API supports radius and bounding-box queries in addition to UPRN and coordinate point lookups. This is useful for development site assessments where you want to understand all nearby conservation area designations within a given distance.
Related data
Conservation Areas API →
Developer reference for the conservation areas endpoint — request parameters, authentication, and response schema.
All Property Data →
Browse all 29 million property data points available through the Homedata API platform.
Planning Permission Data →
Current and historic planning applications across 380 councils, updated daily.