01 What the report is, and who issues it
A coal mining report is a search of the records held by the Mining Remediation Authority, the public body that owns or manages most of the coal and former coal mines in Great Britain. Until the end of November 2024 it traded as the Coal Authority, which remains its legal name, and reports in a data room from before then, and some since, carry the old name. The standard report is the CON29M, a set of enquiries owned by the Law Society and answered by the Authority for a boundary the customer draws. It comes in a residential and a non-residential version; on a commercial site the non-residential version is the one to rely on, and resellers' commercial reports are the official CON29M with the reseller's interpretation and sometimes a ground hazard screen wrapped around it.
Read the front page before the findings. It confirms whether the location is on the coalfield, lists the potential coal mining risks the search found with page references, gives a short professional opinion, and shows the enquiry boundary on a plan. Check that boundary against the red line of the site being sold. A report drawn to the previous owner's title, a single unit, or an older site boundary is not a report on what you are buying, and the buffers the report applies, 20 metres for mine entries and 50 metres for subsidence claims, are measured from the boundary that was searched.
Two limits apply to everything below. The report is based on the Authority's records at the date of the search, and nobody has visited the site. And it is a report on coal: ironstone, limestone, fireclay and other mineral workings, and non-coal mining areas, are outside its scope and need a different search.
The Authority's records cover the coalfields of England, Scotland and Wales; in Scotland the report answers a Scottish form of the enquiries. The Development High Risk Area regime and the risk assessment that goes with it apply across the coalfields of all three nations; the national planning policy and guidance cited in this guide are England's, and Scotland and Wales have their own planning frameworks. Northern Ireland is outside the Authority's remit altogether.
02 On the coalfield, and in which risk area
The Authority publishes two sets of boundaries, and they answer different questions. The Coal Mining Reporting Area is the conveyancing boundary: a site inside it needs a coal mining report for the transaction, and a lender will expect one. The Development High Risk Area and Development Low Risk Area together cover the whole coalfield and are the planning boundaries. A site in the high risk area has recorded features, shallow workings, mine entries, mine gas or former opencast ground, that could affect the stability of new development, and most planning applications there must be accompanied by a coal mining risk assessment. A site in the low risk area still needs the report, but the planning authority will usually do no more than attach an informative note to the consent.
The report does not state which area the site is in. Its future development section only says that a risk assessment may be required in a high risk area, so take the findings, recorded workings, entries, gas or opencast ground, as the signal, and confirm the area on the Authority's online map, which is linked from its property development guidance. That one check decides whether the planning application carries an extra technical document and an extra consultee, so it belongs in the bid programme on day one.
03 The findings, section by section
The body of a CON29M is a list of headed answers. The table sets out what each one is answering and what the answer means for a scheme with heavy floor loads, deep foundations and a large yard.
| Section | What it answers | What it means for the bid |
|---|---|---|
| Past underground coal mining | Whether the site is in the zone of likely physical influence of recorded past workings, how many seams, at what depth, and when last worked. | Shallow workings under a floorplate are a foundation design and ground treatment question. Deep workings worked long ago are usually settled ground, but the depth and the date are the facts to carry into the geotechnical brief. |
| Present and future underground coal mining | Any current workings, any licence considered or granted for future working, and any notice under section 46 of the Coal Mining Subsidence Act 1991. | Rare on modern sites. A live licence or a section 46 notice is a programme and insurance conversation before anything else. |
| Mine entries | Whether any shaft or adit is recorded within the site or within 20 metres of its boundary, with a reminder that unrecorded entries may exist locally. | The finding that moves a bid. See the next section. |
| Coal mining geology | Whether the Authority is aware of damage caused by geological faults or other lines of weakness that coal mining has affected. | Recorded damage along a fault that mining has reactivated is a differential settlement risk and a reason to ask the ground investigation to look for the fault. |
| Past, present and future opencast mining | Past surface mining at the site, any current opencast within 200 metres, and any licence considered or granted for future opencast within 800 metres. | Former opencast ground is backfill, often deep and variably compacted. Expect a ground investigation to concentrate on it, and expect the risk assessment to mention the highwall, the original cut edge, which is typically where differential settlement concentrates. |
| Coal mining subsidence | Whether a damage notice or claim has been made for the site or any property within 50 metres since the end of October 1994, whether a stop notice is in force, and whether preventive works have been requested. | A history, not a forecast. A cluster of claims or a live stop notice means the ground was moving recently and the Authority knows it. |
| Mine gas | Whether a mine gas emission has been reported at the site that required the Authority to investigate and act. | Only recorded incidents. No entry does not mean no gas, and a scheme over workings needs its own gas risk assessment. |
| Hazards related to coal mining | Whether the Authority has carried out emergency remedial works at the site under its surface hazard call-out. | A collapse, a crown hole or an open shaft that someone once reported. Find out what was done and whether it was permanent. |
| Withdrawal of support | Any notice of withdrawal of support, and any revocation under section 41 of the Coal Industry Act 1994. | Mostly historical, but a right to withdraw support that has not been revoked is a title and insurance point. |
| Working facilities orders; former copyhold land | Orders under the Mines (Working Facilities and Support) Acts, and payments relating to former copyhold land. | Rare. Pass to the solicitor if anything is recorded. |
After the findings the report adds a professional opinion, a note of past site investigations the Authority knows about in the area, a summary of the statutory cover for subsidence and hazards, a glossary, and a list of recommended further reports. The site investigation list is easy to skip and worth reading: it names the companies that have already drilled nearby, and their reports can sometimes be obtained.
04 Mine entries: the finding that moves a bid
A shaft or an adit is a hole into the workings, and its position on the Authority's records comes from plans of varying age and accuracy. The report tells you that an entry is recorded within the site or within 20 metres of the boundary; it does not tell you exactly where it is, how it was filled, or whether the filling has held.
The Authority's policy is that building over or within the influencing distance of a mine entry should be avoided where possible, even where the entry has been treated. Where it cannot be avoided, development is permitted only where expert advice supports an engineering design that addresses the safety and environmental risks, including gas and mine water; the Authority accepts no financial or maintenance liability; the engineering precautions protect the public and the structure; and the works are approved and monitored by the Authority's permissions service. The Authority also publishes a zone of influence for each recorded entry, the surface area that could be affected if it subsided, calculated from the size of the entrance, the thickness of the superficial deposits and the source of the record, with a default of 20 metres where the calculation gives less. It is a mathematical zone that ignores local geology, so it is a screening tool rather than an engineering answer, and the influencing distance in the policy is a site judgement rather than that published figure.
For a logistics scheme this is where the report meets the layout. A warehouse floorplate is a large ground-bearing slab, the yard carries heavy axle loads, and neither wants a shaft under it. If the recorded entry falls inside the developable area, the questions before the bid are whether the building can move, whether the yard can be arranged around the zone, and what an intrusive investigation to locate and treat the entry will cost in time. The Authority's own guidance is that entries should be located precisely by intrusive investigation at the layout stage, and a mine entry plan and data sheets, ordered to the same boundary as the report, gives the recorded detail for each one. A reseller's traffic light summary that says the report has passed is a conveyancing judgement about value and lending; it is not a statement that the floorplate fits.
05 Shallow workings and the planning application: the CMRA
The planning system treats unstable land as the developer's problem to resolve. National policy requires a site to be safe, stable and suitable for its proposed use, with the responsibility for a safe development resting with the developer and landowner, and the Planning Practice Guidance on land stability describes the Authority's role and the high risk area regime.
In a Development High Risk Area most planning applications must include a coal mining risk assessment, usually called a CMRA. The exemptions include householder, advertisement and tree works applications, certificates and consents that involve no groundworks, and minor items such as bin stores and solar arrays, none of which help a logistics scheme, and the planning authority can ask for one on any site. The CMRA is a desk-based assessment by a suitably qualified and competent person, ideally signed off by a chartered engineer or geologist with ground investigation experience. It describes the site and the development, the information sources used, the site-specific risks from shallow workings, mine entries, mine gas and opencast highwalls, a strategy for investigating and mitigating them, and a conclusion. It leans on the CIRIA guidance on abandoned mine workings, and it typically ends by recommending intrusive investigation and the treatment it expects to follow.
The Authority is a statutory consultee on the application, though not on the later discharge of conditions, and its response commonly asks for a condition requiring the investigation and remediation the CMRA recommended before development starts, or objects where the assessment is inadequate. For the buyer that means a pre-commencement condition, a drilling programme, possibly a grouting programme, and the permit described next, all on the critical path. A CMRA already in the data room tells you the previous owner got this far and gives you the shape of the works; its absence on a high risk area site means the cost and the time are still unquantified.
06 Permits: piling, boreholes and grouting through coal
Most of the coal and the old workings belong to or are managed by the Authority, so anyone who wants to enter, disturb or change coal, coal workings or a mine entry needs its permit first. That includes drilling site investigation boreholes through a seam, piling or excavating foundations into coal or workings, grouting shallow workings, and capping or filling a shaft or adit. Where excavation for foundations or service trenches will remove coal incidentally, that is covered by a separate incidental coal agreement.
Permit fees are set on a published scale by site area, number of boreholes and number of mine entries, with a separate charge where an entry is to be treated. The standard service takes some weeks from a complete application, and there are faster routes at a multiple of the fee, subject to availability, the fastest of them limited to site investigation work that does not involve a mine entry. Work must not start until the permit certificate has been issued. On a site with coal at shallow depth, therefore, the sequence is report, risk assessment, permit, investigation, possibly a second permit for treatment, then foundations, and each step waits on the one before. A bid programme that shows piling starting the week after planning is a programme that has not read the report.
07 Subsidence, mine gas, and what the report cannot tell you
Subsidence. Under the Coal Mining Subsidence Act 1991, as amended by the Coal Industry Act 1994, the person responsible for the mining must make good subsidence damage caused by coal mining, at no cost to the owner, lender or insurer; for most of the coalfield that is the Authority. A claim is made by serving a damage notice within six years of the owner becoming aware of the damage, and the Authority normally inspects soon afterwards. The report's claims history tells you whether the ground around the site has moved recently enough for someone to claim. It does not tell you whether it will move under a new slab, which is the geotechnical question, and the statutory cover makes good damage to what is there rather than designing out the risk to what you intend to build.
Mine gas. The mine gas section records only emissions reported to the Authority that required it to act, and the report's own glossary says that no record does not mean no gas. Methane and carbon dioxide from coal measures and old workings migrate along workings, shafts and faults, and investigating a seam can itself release or displace gas. A scheme over workings needs a ground gas risk assessment by a competent assessor, and mine gas is assessed differently from landfill gas: the empirical screening methods written for landfill sites are treated with caution on coalfield ground, and there is specific good practice guidance for coal mine gas.
What is not there. No inspection has been made. Workings before systematic plan keeping are often unrecorded, and the report says so. The buffers stop at 20, 50, 200 and 800 metres from the boundary searched. Non-coal minerals are outside the search entirely. The report is the start of the ground story on a coalfield site, and the ground investigation report is where it continues.
08 Red flags to catch before you bid
Some findings should change the number or the programme. A recorded mine entry inside the developable area is a layout constraint until an intrusive investigation has found it, and a floorplate that cannot move around it is a scheme risk. Shallow workings under the footprint mean ground treatment, a permit and a pre-commencement condition. A site in a Development High Risk Area with no CMRA in the data room means the planning application carries an unquantified technical document and an extra consultee.
Then the ground history. Former opencast ground is deep backfill with a highwall somewhere under it, and the ground investigation should be scoped to find both. A live stop notice or a cluster of recent subsidence claims means the Authority knows the ground has moved. A recorded hazard call-out is a collapse someone once reported. A report drawn to the wrong boundary, or a residential report on a commercial site, is not a report on what you are buying. And a reseller summary that says the site has passed answers a lender's question, not a developer's.
None of these is unusual on coalfield land, and plenty of logistics parks have been built across all of them. The point of reading the report before a bid is to put the investigation, the treatment and the permits in the programme and the price, rather than discovering them when the piling rig is on site.
09 Frequently asked questions
What is a coal mining report?
A coal mining report is a search of the Mining Remediation Authority's records for a defined boundary, answering a standard set of questions about past, present and future coal mining under and around the land. The standard form is the CON29M, a set of enquiries owned by the Law Society and answered by the Authority, which until November 2024 traded as the Coal Authority. It reports recorded underground workings, mine entries within 20 metres of the boundary, opencast mining nearby, subsidence damage claims, reported mine gas and hazard incidents, and any notices affecting support. It is a records search rather than an inspection: nobody visits the site, and the report says what the Authority knows, not what is in the ground.
Do I need a coal mining report for a commercial property?
If any part of the site lies within the Coal Mining Reporting Area, the standard conveyancing answer is yes, and a lender will expect one. The Authority publishes that area, and the reseller or search provider will tell you at the ordering stage whether the site is inside it. The commercial version of the CON29M is the non-residential report; a residential report on a commercial site is not something to rely on. For an industrial or logistics acquisition the better question is not whether to buy the report but what to buy with it: on a site with recorded entries or shallow workings, a mine entry plan or a consultant's interpretive report turns a list of records into something a layout can be designed around.
How much does a coal mining report cost?
The standard report is a small item in a pre-bid budget. The Mining Remediation Authority publishes a price list each year; non-residential reports are priced by the size of the site, in hectare bands, with a surcharge where the Authority rather than the customer draws the boundary. Search resellers bundle the official report with their own interpretation and ground hazard data at a modest premium. The costs that are not small are the ones the report may lead to: a mine entry plan and data sheets, an intrusive investigation to locate shafts, a coal mining risk assessment for the planning application, and the permit fees for piling or drilling through coal, which are set on a published scale by area, borehole and mine entry count.
How long is a coal mining report valid for?
The report has no stated validity period. It reflects the Authority's records on the day of the search, and the Authority's own guidance is that there is no general time protection of the information and that anyone in doubt about an older report should order a new one. In practice the records change slowly, so a report in a data room from a recent transaction is a useful read; a report that predates a change in the Authority's data, or that was drawn to a different boundary from the site being sold, is not one to rely on for a bid. Lenders have their own conventions about search age, and a lender's solicitor will say if a fresh one is needed.
What is the difference between a coal mining report and a coal mining risk assessment?
The report is a records search; the risk assessment is a professional opinion about what those records mean for a specific development. A CON29M says whether there are recorded workings, entries, claims and notices within set distances of the boundary. A coal mining risk assessment, usually called a CMRA, is a desk-based assessment by a suitably qualified person that takes the report, the geological and mining records and the proposed layout, identifies the site-specific risks from shallow workings, mine entries, mine gas and opencast highwalls, and sets out a strategy to investigate and mitigate them. In a Development High Risk Area most planning applications must be accompanied by a CMRA, and the Authority is a statutory consultee on the application. A buyer reading a data room will usually find the report; finding a CMRA as well tells you the previous owner got as far as thinking about a scheme.
What is a Development High Risk Area?
The Mining Remediation Authority divides the coalfield into Development High Risk Areas and Development Low Risk Areas for planning purposes. A high risk area is one where recorded coal mining features, such as shallow workings, mine entries, mine gas or former opencast sites, could affect the stability of new development. In a high risk area most planning applications, with exemptions such as householder, advertisement and tree works applications and minor works with little groundwork, need a coal mining risk assessment, and the planning authority consults the Authority on them. In a low risk area the site is still on the coalfield and still needs a coal mining report for the transaction, but the planning authority will normally impose only an informative note. The report itself does not say which area the site falls in; the recorded features point one way or the other, and the Authority's online map confirms it.
What does a mine entry within 20 metres mean for development?
It means a recorded shaft or adit lies within the site or within 20 metres of its boundary, and that the layout cannot be settled until it has been found. The Authority's policy is that building over or within the influencing distance of a mine entry should be avoided where possible, even where the entry has been treated, and is permitted only where expert advice supports an engineering design that deals with stability, gas and mine water, the precautions protect the public and the structure, and the Authority's permissions service has approved and will monitor the works. The Authority also publishes a calculated zone of influence for each recorded entry, worked out from its size, the thickness of the superficial deposits and the quality of the record, with a default of 20 metres where the calculation gives less; the influencing distance in the policy is a site judgement informed by it. Recorded positions can be some distance out, so the first step on site is an intrusive investigation to locate the entry precisely, and a logistics floorplate that cannot move around it is a scheme risk rather than a design detail.
Can you build over a mine shaft?
Sometimes, but it is the Authority's stated last resort rather than a design choice. Its policy is to avoid building over or within the influencing distance of a mine entry wherever possible, treated or not. Where there is no alternative, development is allowed only on four conditions: expert advice supports an engineering design that addresses the safety and environmental risks including gas and mine water, the Authority takes no financial or maintenance liability, the engineering precautions protect people and structures, and the works are approved and monitored through the Authority's permissions service. On a logistics site the practical answer is usually to find the shaft, cap it to the Authority's requirements, and keep the building and the heavy yard loads outside its zone of influence, which is a layout constraint to know about before the bid rather than after.
Who pays for coal mining subsidence damage?
Under the Coal Mining Subsidence Act 1991, as amended by the Coal Industry Act 1994, the person responsible for the mining has to make good subsidence damage caused by coal mining, at no cost to the owner, lender or insurer. For most of Great Britain that person is the Mining Remediation Authority. A claim is made by serving a damage notice within six years of the owner becoming aware of the damage, and the Authority normally inspects soon after. The report's subsidence section tells you whether a damage notice or claim has been made for the site or any property within 50 metres since the end of October 1994, whether a stop notice deferring permanent repair is in force, and whether preventive works have been requested. A claims history is not a reason to walk away, but a live stop notice, or a cluster of claims around the site, is a reason to ask what is still moving.
Do I need a permit to pile through coal?
Yes. Most coal and former coal mines are owned or managed by the Mining Remediation Authority, and anyone who wants to enter, disturb or change coal, coal workings or a mine entry needs a permit from it first. That covers drilling site investigation boreholes through a seam, piling or excavating foundations into coal or workings, grouting shallow workings, and capping or filling a shaft or adit. Where foundations or service trenches will remove coal incidentally, that is covered by a separate incidental coal agreement. Fees are set on a published scale by site area, number of boreholes and number of mine entries, and the standard service takes some weeks, with faster routes at a multiple of the fee, subject to availability. Work must not start until the permit certificate is issued, so on a site with coal at shallow depth the permit is on the programme's critical path and belongs in the bid assumptions.
Read the ground story across the whole pack, not one search
Plumb reads the coal mining report alongside the ground investigation, the contamination reports, the planning history and the title in a deal's data room, pulls out the recorded entries, workings and claims with their distances from the boundary, checks the boundary searched against the red line, and says where the pack leaves a question open, such as a high risk area site with no risk assessment or a shaft the layout has not been drawn around. Every point is cited back to the page it came from, so your read is easy to defend in committee.