If you are developing land anywhere across the West or South Yorkshire coalfield, the phrase 'coal mining risk assessment' will appear at some point - usually in a planning validation checklist, and usually later than would have been convenient. It is worth understanding what it is before that happens.
What it is
A coal mining risk assessment is a report supporting a planning application, assessing the mining legacy beneath and around a site and what it means for what is proposed. It is required for development within the areas defined as at higher risk from coal mining legacy - shallow workings, mine entries, and the other features that centuries of extraction left behind.
The records sit with the Mining Remediation Authority, formerly the Coal Authority, which is the public body responsible for the coal mining legacy in Britain. Local planning authorities across the coalfield - Bradford, Sheffield, Doncaster, Barnsley, Rotherham, Wakefield and others - require the assessment for development in the defined higher-risk areas.
It is not the same as your conveyancing search
This confuses people constantly, and the two documents do different jobs.
- A coal mining report is the search a solicitor obtains when a property changes hands. It reports what the records show for that address - past workings, mine entries, subsidence claims, and whether the property is in an area where the Authority holds relevant information. It is a disclosure document for a buyer.
- A coal mining risk assessment is a planning document for a development proposal. It interprets the same underlying records, but it assesses risk in the context of what is being built, and it recommends what should be done about it - intrusive investigation, treatment of workings, foundation solutions, or nothing.
A clean conveyancing search does not remove the planning requirement, and having commissioned one does not mean you have the other.
What a good one contains
- A desk study of the mining records: abandonment plans, recorded seams and their depths, mine entries within an appropriate distance of the site, and any recorded subsidence
- Historic mapping, which frequently shows surface features - shafts, spoil, tramways, opencast - that the mining records alone do not
- The site's geology, and what that means for how a working at a given depth would behave
- An assessment of the actual risk to the proposed development, which depends as much on what is being built and where as on what is underneath
- Recommendations proportionate to that risk - which may be further intrusive investigation, may be treatment such as grouting of workings or capping of an entry, may be a foundation solution, and may legitimately be that no further action is needed
- Clear conclusions a planning officer can condition against
The limitation nobody should gloss over
The records are not complete, and no competent assessment pretends otherwise. Coal was worked in this region for centuries before anybody was required to record it, and the oldest workings - which are also the shallowest, and therefore the ones most likely to affect a building - are the least well documented.
That is not a reason to distrust the process. It is the reason the process includes intrusive investigation where the desk study leaves real doubt: drilling to prove whether a working is actually there, rather than relying on a plan drawn in 1870 or not drawn at all.
What it means for foundation design
This is the part that costs money when it is done in the wrong order. The assessment should inform the foundation design, which means it needs to exist before the foundations are designed - not after the layout is fixed, the drawings are issued and the ground investigation contractor is being chased.
The sequence that works, on any site in the coalfield: establish the mining position, get the ground investigated where the assessment says it is needed, then design the foundations to what has actually been found. Fitting foundations retrospectively to a report that arrived late is the single most common avoidable cost we see on development sites across this region.
Does a homeowner need one?
Normally not. It is a planning requirement attached to development, not something an owner of an existing house commissions. If you own a house in a mining area and are worried about cracking, what you need is a structural inspection that establishes what has actually caused it - and the mining question is one of several the engineer will consider, alongside far more likely explanations such as thermal movement, a failed lintel, wall tie corrosion or a leaking drain.
If a structural assessment does point at mining, it is worth knowing that damage caused by coal mining subsidence has its own statutory compensation scheme, separate from ordinary buildings insurance. That changes who investigates and who pays, so it is worth establishing early.
Where we fit
Mining legacy is central to how we assess ground across this region, and on a development site we co-ordinate the mining position, the ground investigation and the foundation design as one sequence rather than three separate exercises. Tell us the site and the application and we will confirm what is actually required before you commission anything - including when the answer is that you do not need what you have been quoted for.
Frequently asked questions
When is a coal mining risk assessment required?
When development is proposed within an area defined as at higher risk from coal mining legacy. Local planning authorities across the West and South Yorkshire coalfield require it as part of a valid application in those areas, and it is normally listed on the authority's validation checklist.
Is it the same as the coal mining search my solicitor did?
No. A coal mining report is a conveyancing search reporting what the records show for an address, for the benefit of a buyer. A risk assessment is a planning document that interprets the same records against a specific development proposal and recommends what should be done. A clean search does not satisfy the planning requirement.
What if the records show nothing?
It is reassurance rather than proof. Coal was worked here for centuries before recording was required, and the oldest and shallowest workings are the least well documented. Where the desk study leaves genuine doubt on a site that matters, intrusive investigation - drilling to prove whether a working is there - is what turns an absence of records into an answer.
Do I need one to build an extension?
Usually not, though it depends on the authority and the location. The requirement attaches to development in defined higher-risk areas, and the threshold varies. Ask the authority before you commission anything - it is a short question and the answer is free.
My house has cracked and I live in a mining area. What should I do first?
Get a structural inspection rather than a mining report. The engineer establishes what has actually caused the damage, and on the balance of probability it will be thermal movement, a lintel, wall ties or a leaking drain rather than the ground. If the assessment does point at mining, the statutory compensation scheme for coal mining subsidence is a separate route from ordinary buildings insurance and is worth identifying early.