Buying in a former coal mining area: surveys and searches

If you are buying in a former coal mining area, your conveyancer should order a CON29M coal mining search, which uses Mining Remediation Authority records to tell you about past and future mining, mine shafts, subsidence claims and mine gas near the property. A house survey adds to this by looking for physical signs of ground movement. Together they help you decide whether any mining legacy is a real risk to the property or simply part of the local history.

Key points

• Large parts of England and Wales sit on former coalfields, from the North East and Yorkshire to the Midlands and South Wales.
• A CON29M search is the official coal mining report used in conveyancing.
• The Coal Authority is now called the Mining Remediation Authority.
• Your surveyor looks for signs of movement, but cannot see underground workings.
• Mine entries close to the house may need a specialist assessment before your lender proceeds.

Why does coal mining matter when buying a house?

Centuries of coal mining left a network of shallow workings, shafts and adits under many towns and villages. Most never cause any problems, but in some cases old workings can collapse, causing ground movement at the surface, or shafts can fail if they were not properly filled and capped. Mine gas can also migrate through the ground in some locations.

The good news is that coal mining is well recorded. The Mining Remediation Authority holds extensive records and has statutory duties to deal with claims for damage caused by past coal mining.

What does a CON29M search show?

The CON29M is the Law Society's coal mining search form. The report typically covers:

• Past underground coal mining beneath or near the property, and its approximate depth and date.
• Present and future underground mining licences and proposals.
• Mine entries (shafts and adits) within a set distance of the property.
• Coal mining geology, such as fault lines and outcropping coal seams.
• Past and present opencast mining nearby.
• Subsidence claims made against the property and any remedial works.
• Mine gas emissions reported in the area.
• Hazards reported to the Mining Remediation Authority, such as collapses.

Your conveyancer will explain the results and raise further enquiries if needed. Some search providers also offer enhanced reports that include an opinion on the risk and whether it is likely to concern lenders.

What does a house survey add?

A Level 2 Home Survey or Level 3 Building Survey is a visual inspection of the building and its surroundings. In a mining area, the surveyor will pay particular attention to:

• Cracking and distortion in walls, especially diagonal or tapering cracks.
• Sloping floors, doors and windows out of square.
• Signs of past repairs, such as rebuilt sections of wall or tie bars.
• Ground conditions in the garden, such as depressions or uneven ground.
• Neighbouring properties showing similar damage.

The surveyor cannot see underground or interpret mining records in detail, so they work alongside your searches. If the survey finds signs of movement and the CON29M shows shallow workings or a nearby shaft, that combination needs following up. Our guides to subsidence and cracks in walls explain how surveyors read movement.

What if there is a mine shaft near the house?

A mine entry close to a property is the finding that most often causes concern. Questions to ask:

• How close is it? A shaft some distance from the house is very different from one within the garden or under the building.
• Has it been treated? Shafts that were filled and capped to modern standards are much lower risk than those of unknown treatment.
• How accurate is the location? Old records are sometimes approximate, and the Mining Remediation Authority may indicate a zone of uncertainty.

Lenders may want an engineer's assessment or a specialist report if a mine entry is within or near the boundary. In some cases a site investigation is recommended. This can add time and cost, so raise it early.

Who is responsible for mining subsidence damage?

Under the Coal Mining Subsidence Act 1991, damage caused by past coal mining is generally the responsibility of the Mining Remediation Authority or the relevant licensed operator, rather than the homeowner's insurer. If you suspect a mining-related hazard, such as a sudden hole or collapse, you can report it to the Mining Remediation Authority, which operates an emergency line.

The CON29M will show whether a claim has been made in the past and whether repairs were carried out. Ask for documents if it has.

What about other types of mining?

Coal is not the only legacy to consider:

• Cornwall and parts of Devon have extensive tin, copper and other metal mining. A specialist Cornish mining search is usually recommended. Some homes in these areas may also need mundic testing of concrete blocks, covered in our non-standard construction guide.
• Cheshire has a history of brine extraction, which can cause subsidence. A brine search may be recommended.
• Limestone, chalk, clay, ironstone and gypsum workings exist in various parts of the country.

Your conveyancer will know which searches are appropriate for the area.

Mining areas and radon

Some former mining areas also have elevated radon levels because of the underlying geology. It is worth checking the radon status of the property too. See our guide to radon and buying a house.

Should you avoid buying in a mining area?

Not usually. Millions of people live on former coalfields without problems, and property can offer good value. The key is to read the CON29M carefully, get a proper survey, and follow up anything unusual before exchange. If movement is evident or a mine entry is close, a Level 3 Building Survey and an engineer's report may be worth the extra cost.

If you are buying on the old coalfield and want a local surveyor who knows the area, get a fixed-price survey booked. You can also browse our locations pages.

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