Does a mining search mean I cannot build?

Rarely. Most findings are managed by repositioning the building or by an engineered foundation. The searches that stop a project usually reveal an uncapped shaft in the only buildable part of a very small plot.

Is a mining search the same as a standard conveyancing search?

A specific Cornish mining search goes further than a general environmental search and is worth commissioning in the historic mining districts.

Only where competent ground is deep or unreliable. Many sites are resolved with a reinforced raft or by moving the footprint a short distance.

Does this affect extensions as well as new builds?

Yes. An extension adds load in a new place, and where the existing house sits close to a recorded feature the new foundations need the same thought.

Ground · Cornwall

Mining legacy and ground conditions in Cornwall, the questions to ask before the foundation design

Cornwall's ground carries several centuries of industry. Around Redruth, Camborne, St Agnes, St Just and large parts of the central mining district, shafts, adits, backfilled workings and made ground are common enough that they should be assumed present until shown otherwise. This is not a reason to avoid a site. It is a reason to spend a small amount on investigation before spending a large amount on a design that the ground will not accept.

Book a free consultation See built work

Free · No obligation

Ask us about your project

A free first conversation — no obligation, no sales calls.

What the legacy actually looks like

Mining ground presents in a small number of recognisable ways, and each one leads to a different engineering response. The point of an early appraisal is to identify which you are dealing with rather than to price for the worst case.

Recorded and unrecorded shafts, sometimes capped historically with timber or rubble rather than concrete
Shallow adits and stopes running under gardens and lanes
Deep made ground from burrows and processing waste, variable and poorly compacted
Granite or killas close to the surface, which changes excavation cost rather than risk
Localised contamination associated with historic processing

Searches, desk studies and intrusive investigation

A mining search and desk study is inexpensive and tells you what is recorded. Records are incomplete, so on higher risk sites a desk study is normally followed by intrusive investigation, trial pits or boreholes positioned where the building is actually going. The order matters: pay for the cheap information first, and let it decide whether you need the expensive information.

How it changes the design

Findings usually resolve into one of a few responses. Move the building away from the feature, which is by far the cheapest answer where the plot allows it. Bridge or raft over variable ground. Pile to competent strata. Grout and cap a shaft under an engineer's design. All of these are ordinary Cornish construction, but each has a very different cost, and discovering which one applies after planning consent has fixed the position of the house is an avoidable expense.

Planning, warranties and lenders

A planning officer may condition a contaminated land or stability assessment. A structural warranty provider will want to see the investigation and the foundation design. A lender's valuer may raise the mining history at the point of sale. All three are satisfied by the same evidence, so commissioning it properly once serves the whole project.

Frequently asked

Straight answers.

Does a mining search mean I cannot build?: Rarely. Most findings are managed by repositioning the building or by an engineered foundation. The searches that stop a project usually reveal an uncapped shaft in the only buildable part of a very small plot.
Is a mining search the same as a standard conveyancing search?: A specific Cornish mining search goes further than a general environmental search and is worth commissioning in the historic mining districts.
Will I need piling?: Only where competent ground is deep or unreliable. Many sites are resolved with a reinforced raft or by moving the footprint a short distance.
Does this affect extensions as well as new builds?: Yes. An extension adds load in a new place, and where the existing house sits close to a recorded feature the new foundations need the same thought.

Building in the mining district?

Send us the address. We will tell you what searches and investigation the site warrants before you commit to a layout.

Free · No obligation

Book your free consultation

Tell us about your project — we usually reply within 2 hours (working day).