Ground Risk Map
UK subsidence map
Subsidence in the UK is overwhelmingly a clay story, and clay is not evenly distributed. This map plots 46 cities at their real coordinates, shaded by the BGS GeoSure clay shrink-swell susceptibility band for the surrounding ground. The pattern it shows is the one insurers price against: a heavy concentration in the south and east, and a different problem entirely — historic mining — across the former coalfields.
Coverage: the 46 cities in our index, across England, Wales and Scotland. Scotland is represented by Aberdeen alone, and Northern Ireland is not in the index, so the plot is not a complete national picture — it is the indexed cities, drawn where they actually are.
Read this before you read the map
This describes ground, not buildings. Most houses on very high susceptibility clay never move. Foundation depth, drainage condition and how close a mature tree sits to the wall decide that, and none of them are visible from a national map. Treat a high band as a question for the surveyor, not an answer.
MyPropertyScan editorialNot a surveyor
Last updated: 10 August 2026. Editorially reviewed: 20 May 2026.
Run the check
Check subsidence signals for a UK address in 15 seconds
Directional BGS 1:1 million engineering geology, building age, tree context and the things to ask your surveyor.
Run a free previewWhere the clay actually is
Three clay formations account for most of the pattern above.
- London Clay. A stiff blue-grey marine clay under London, south Essex, north Kent and parts of Hertfordshire. It is the textbook UK shrink-swell geology and the reason London sits alone in the top band.
- Oxford Clay. Runs north-east from Oxfordshire through Buckinghamshire, Bedfordshire and Cambridgeshire — the belt that puts Oxford, Milton Keynes, Luton, Peterborough and Cambridge in the moderate-to-high band.
- Gault and Weald clays. Across Surrey, Sussex and west Kent, and along the central south coast behind Portsmouth and Southampton.
Everywhere else, the dominant ground question changes. In the former coalfields it is historic workings and a Coal Authority search; see coal mining risk when buying. On the chalk of Norfolk and parts of the south it is historic chalk and flint workings. In Hull and Carlisle it is soft alluvial ground rather than clay at all.
Highest-band cities
The 10 cities in the moderate-to-high band or above. Each links to its local subsidence guide, which covers the specific geology, mining history and tree context for that city.
| # | City | Band | Primary driver |
|---|---|---|---|
| 1 | London | Very High | Clay shrink-swell |
| 2 | Chelmsford | High | Clay shrink-swell |
| 3 | Cambridge | Moderate–High | Clay shrink-swell |
| 4 | Luton | Moderate–High | Clay shrink-swell |
| 5 | Milton Keynes | Moderate–High | Clay shrink-swell |
| 6 | Oxford | Moderate–High | Clay shrink-swell |
| 7 | Peterborough | Moderate–High | Clay shrink-swell |
| 8 | Portsmouth | Moderate–High | Clay shrink-swell |
| 9 | Reading | Moderate–High | Clay shrink-swell |
| 10 | Southampton | Moderate–High | Clay shrink-swell |
The full 46-city ranking, including the lower bands and the mining cities, is in the UK Subsidence Risk Index.
How this map was built
Cities ranked by BGS GeoSure clay shrink-swell susceptibility band (the dominant UK subsidence driver), with significant historic mining listed first within each band, then alphabetically. Primary driver reflects each city's headline ground-stability factor. Bands are categorical (Low to Very High), not claim counts.
Positions are each city's published latitude and longitude on an equirectangular projection with a cosine correction at 53.8°N. No coastline is drawn — the shape you see is produced entirely by where the cities are, which means there is no traced outline to be subtly wrong. Gridlines mark whole degrees.
For national context: ABI: the 2022 heatwave drove an expected £219m subsidence bill (highest since 2006) from ~23,000 claims.
Source: British Geological Survey (BGS) GeoSure shrink-swell susceptibility, summarised per city; national claims context from the Association of British Insurers (ABI). Licence: Custom MyPropertyScan reuse terms: citation and short extracts permitted with attribution; underlying BGS and ABI rights retained. See https://www.mypropertyscan.com/subsidence-risk-index#data-licence.
Frequently asked questions
Which parts of the UK have the highest subsidence risk?
The clay belts of southern and eastern England. London Clay under the capital and the Thames estuary is the single highest-risk geology, followed by the Oxford Clay belt through Oxfordshire, Buckinghamshire and Cambridgeshire, and the Gault and Weald clays across Surrey, Sussex and Kent. Northern and western cities generally sit on sandstone, limestone or granite, where the dominant ground risk is historic mining rather than clay shrink-swell.
Is there a subsidence map for my area?
The British Geological Survey publishes shrink-swell susceptibility mapping as GeoSure, which is address-level and licensed. This map summarises that picture at city level for the 46 cities in our index, covering England, Wales and one Scottish city, with Northern Ireland not included. For a specific property, the parcel-level answer comes through your conveyancer's environmental search rather than from any free national map.
Does a high-risk area on the map mean the house has subsidence?
No. The map describes the ground, not the building. Most houses on high-susceptibility clay never move, because foundation depth, drainage condition and tree proximity matter as much as geology. A high band means the question is worth asking of a surveyor, not that there is a problem.
Why do northern cities show mining rather than clay?
Clay shrink-swell is concentrated in the south and east because that is where the relevant marine clays outcrop. In the former coalfields — Nottingham, Sheffield, Stoke-on-Trent, Doncaster, Swansea and the North East — ground stability questions are more often about historic workings, which is a Coal Authority search rather than a clay question.
Run the check
Check subsidence signals for a UK address in 15 seconds
Directional BGS 1:1 million engineering geology, building age, tree context and the things to ask your surveyor.
Run a free previewKeep going
Related guides
- Subsidence risk postcode checker , the clay band and local mining context for a specific postcode.
- Buying a house with subsidence , how to tell active movement from historic, and when to walk away.
- Bought a house with subsidence , disclosure, insurance and what your options are once you already own it.
How MyPropertyScan produces this guide, and what it is not
Published by MyPropertyScan and written by Ziad Nasr, who is accountable for its accuracy. No page here is written or reviewed by a chartered surveyor, conveyancer or regulated adviser, and we do not claim otherwise.
This page is not:
- Chartered surveying — we do not inspect properties or produce RICS Home Survey reports
- Legal advice — we do not act as conveyancers or advise on title, tenure or contracts
- Mortgage or insurance advice — we are not regulated by the FCA and give no recommendations
Figures and process steps come from the published UK datasets and standards listed on this page, not from professional practice. Pages are updated when source coverage, survey cost assumptions, or lender and legal requirements materially change. Dataset limitations are set out on the methodology page.
Spotted something out of date or wrong? Email hello@mypropertyscan.com and we will correct it and change the update date.
Sources used
We use UK public and specialist sources where they are available. Public datasets can be incomplete, delayed, or missing for some addresses. Treat them as a starting point, not as a replacement for professional advice.
Source standard: preference goes to official government datasets, statutory bodies, professional standards, and primary dataset publishers. We cite the source family on the page and explain coverage limits rather than filling gaps with unsupported estimates.
- Check this with: Environment Agency long-term flood risk mapOfficial flood-risk service for England, including river, sea, surface water, reservoir and groundwater where available.
- Data source: HM Land Registry Price Paid DataRegistered residential sale prices for England and Wales.
- Official register: Energy Performance Certificate RegisterPublic EPC certificate lookup for an address, postcode, street or certificate number.
- Data source: British Geological Survey Engineering Geology (1:1 million)National-scale bedrock and superficial-deposit mapping used as a directional ground indicator, not parcel-level GeoSure data or a site investigation.
- Data source: Copernicus CAMS via Open-MeteoCurrent modelled PM2.5, NO₂ and European AQI from a nearby CAMS grid cell.
- Data source: DEFRA Environmental Noise Directive mappingMapped road and rail noise contour data for England, classified into MyPropertyScan's low/moderate/high bands, and separate from the CAMS air-quality source.
- Data source: Police.uk crime dataOpen street-level crime data for England, Wales and Northern Ireland.
- Check this with: Ofcom broadband checkerOfficial checker for broadband availability and speeds.
- Check this with: Ofcom mobile coverage checkerOfficial predicted mobile coverage by network.
- Data source: Food Standards Agency food hygiene ratingsPublic register used to identify nearby food and drink venues.
- Official register: Ofsted inspection reportsSchool and provider inspection report lookup for England. Fee-paying schools come from the DfE Get Information About Schools register, since around half are inspected by ISI and carry no Ofsted grade.
- Official register: Historic England National Heritage ListListed buildings, scheduled monuments and other protected heritage entries in England.