Subsidence Check by Postcode — Ground, Coal & Sinkhole Risk

Run a subsidence check by postcode on any UK property. Enter a postcode and HouseCheckup screens British Geological Survey (BGS) GeoSure and Coal Authority data to flag shrink-swell clay subsidence, landslide susceptibility, compressible and collapsible ground, running sand, dissolution (sinkhole) hazards and former coal mining — the underground risks that decide whether a home is insurable and what it's worth. No other tool brings BGS GeoSure and coal-mining screening together like this. The £24.99 Complete report adds the full ground stability assessment with plain-English risk explanations for a specific address, alongside flood, EPC, crime and 70+ other checks.

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Instant results from official UK government data.

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This tool checks one data point. The HouseCheckup Complete report combines 70+ data sources into an 18-page report with a composite IQ Score (0–100) — covering flood, EPC, crime, schools, transport, ground stability, investment potential, and more. One report, one price — £9.99 Lite / £24.99 Complete. No subscription, no auto-renew.

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What a subsidence check by postcode tells you

A subsidence check by postcode screens the official ground-hazard datasets for the area around a property so you can spot underground risk before you pay for surveys, searches or a structural engineer. HouseCheckup combines two official government sources: the British Geological Survey (BGS) GeoSure suite for natural ground movement, and Coal Authority data for former and present coal workings. It is a desk-based first filter — area and point-level data a surveyor cannot see by walking the property — not a substitute for a structural survey or a formal mining report.

What causes subsidence in the UK?

The dominant cause in England and Wales is shrink-swell clay: clay-rich soils swell when wet and shrink in dry spells, moving foundations. Roughly a quarter of UK homes sit on shrink-swell ground, and the risk is rising with hotter, drier summers. Other causes the GeoSure layers cover are landslides (slope instability), compressible and collapsible ground, running sand, and dissolution of soluble rocks — the mechanism behind most natural sinkholes.

Coal mining and ground stability

Around a quarter of properties in England and Wales lie within a coalfield. Old shallow workings can cause ground movement, and lenders often require a Coal Mining Risk Assessment (CON29M) where the address falls in a referral area. Our check flags coal-mining risk from Coal Authority data alongside the natural ground hazards, so you know up front whether a mining report is likely to be needed. For a deeper, single-hazard view, see the coal mining risk check.

Sinkhole and dissolution risk

Sinkholes form where chalk, limestone or gypsum dissolves underground and the surface collapses into the void. The GeoSure soluble-rocks layer screens for this, and our checker surfaces it as part of the subsidence result. A flag is a prompt to investigate, not a verdict — it means dissolution features are plausible in the area and a specialist ground investigation may be warranted before purchase.

Why subsidence risk affects price and insurance

Subsidence is one of the few risks that can directly stop a sale or inflate costs for the life of the home. Properties with a subsidence history, or in high-risk ground, can face higher insurance premiums and excesses, and buyers routinely use a flagged risk to renegotiate. Checking the ground before you offer lets you price the risk in — or walk away — rather than discovering it during a failed mortgage valuation.

From a postcode screen to a full address report

The postcode check works at postcode level. When you've shortlisted a property, the Complete report (£24.99) goes deeper on the specific address, combining the ground-stability assessment with flood risk, radon, the EPC and 70+ further official sources in one place — the underground and environmental picture that decides whether a home survives due diligence.

Frequently asked questions

The main cause of subsidence in England and Wales is shrink-swell clay. During dry periods, clay soils shrink and can cause foundations to move. About 25% of UK homes are on shrink-swell clay. Other causes include mining activity, natural dissolution of soluble rocks, and compressible ground. HouseCheckup checks all of these using BGS GeoSure data.
Yes. HouseCheckup checks Coal Authority data for past, present, and planned coal mining activity. Properties in coal mining areas may be affected by subsidence from old mine workings. The Complete report includes detailed coal mining risk assessment alongside BGS ground stability data.
Properties with a history of subsidence or in high-risk areas may face higher insurance premiums or excesses. Insurers often check BGS data when underwriting. HouseCheckup's ground stability check helps you understand the risk before purchasing, so you can factor insurance costs into your decision.
Enter a postcode in the checker at the top of this page and HouseCheckup screens British Geological Survey GeoSure data for shrink-swell clay, landslides, compressible and collapsible ground, running sand and soluble-rock dissolution, plus Coal Authority mining data — instantly. It is an area-level screen of the official datasets, not a survey: it tells you whether the ground beneath a property warrants a closer look before you commit to expensive checks.
Yes, indirectly. Sinkholes form where soluble rocks such as chalk, limestone or gypsum dissolve underground. The BGS GeoSure dataset includes a soluble-rocks (dissolution) layer, which our check screens alongside the other ground-stability hazards. A flag means dissolution features are possible in the area and a specialist ground investigation may be worth commissioning — it does not mean a sinkhole is present at a specific address.
No, but they overlap. A subsidence check screens natural ground hazards (clay shrink-swell, landslides, dissolution). A coal mining search looks specifically at risks from former and current coal workings. HouseCheckup screens both — BGS GeoSure for natural ground movement and Coal Authority data for mining. Where coal risk is flagged, a buyer or lender may still require a formal Coal Mining Risk Assessment (CON29M), which the Coal Authority provides.

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