Inside SIC 43130: The £405m UK Ground Investigation Market

A summary of the Construct365 Sector Intelligence Report on SIC 43130 — the Companies House classification for test drilling and boring, the code that holds the UK's ground investigation contractors. The full 26-page report, with the operator composite, the technology-stack tables and the sourcing caveats, is a free direct download — no email address required.

Disclosure: Section 10 of the report assesses QuoteAgent, which is a Construct365 product — and concludes it does not fit this sector. The report reaches a negative verdict about our own product, and this summary repeats it rather than softening it.

A niche, not a sector — and half its register doesn't belong

Ground investigation is small. The report puts industry revenue at about £405m in 2026, growing at roughly 2% nominal, shared among around 310 real operating businesses. Individual framework awards are large enough to move the whole market number.

The more striking figure is the one behind it: Companies House lists roughly 600 active companies under SIC 43130 — nearly double the real population. The gap is misregistration, not measurement noise. The word "drilling" pulls in concrete coring outfits, mini-piling contractors and water-well drillers that belong under other codes entirely. The report's practical warning: any screen, directory or ranking built on the raw 43130 register will overstate the population by about 90%, so it has to be hand-cleaned against AGS or BDA membership or evidence of genuine site investigation work.

There is no van-and-a-phone tail here either. Entry requires rigs, a support fleet, laboratory access, BDA accreditation and framework working capital — which is why 310 firms exist rather than 45,000, and why concentration is high and rising: the report estimates the four largest groups hold 25–35% of revenue (CR4), with RSK alone having assembled four separately-branded ground investigation businesses by acquisition.

The risk paradox

This is the report's central finding, and the sector's own trade bodies said it first. Unforeseen ground conditions are cited as the cause of up to half of all construction project overruns. Ground investigation is the activity that exists to retire that risk, it costs a fraction of a per cent of project value — and it is routinely awarded to the lowest bidder, on a scope written by a non-specialist, too late in the programme to influence design.

The British Drilling Association has described ground investigation procurement as "broken and desperately in need of a fundamental change", and AGS/BDA industry surveys have repeatedly ranked poor procurement among the sector's top concerns. The report's structural read is that this is an incentive failure, not a knowledge failure: the consultant buying the investigation is rarely the party who carries the ground risk, so buying the minimum is rational for the buyer and irrational for the project. A decade of best-practice guidance addresses understanding; none of it addresses incentive.

Digitised data, Victorian drilling

SIC 43130 holds a paradox no other trade in Division 43 can match. Its data has been structured and machine-readable since 1991, when the AGS interchange format was established — before the commercial web — and the British Geological Survey runs a national public borehole archive on top of it. Yet the AGS itself observes that many traditional investigation methods "have not changed in the past 100 years." Cable percussion boring is a Victorian technique with a cloud API bolted onto the paperwork.

The report notes what the stack still misses: nothing in it touches the commercial step of turning a sixty-page specification into a priced bill of quantities. The sector standardised its output and left its input — the tender — entirely unstructured.

Water is the demand story; labour is the constraint

The AMP8 water investment cycle commits on the order of £100bn, with the environmental programme (WINEP) alone at £22.1bn — four times the previous price review — and Anglian Water is bringing a single £35m ground investigation framework to market in August 2026. If other water companies follow proportionally, water alone becomes a double-digit share of this code's annual revenue for years.

The binding constraint will not be demand. Drillers need BDA accreditation and an NVQ in Land Drilling, the geotechnical profession is openly debating a decline in engineering expertise, and 27% of the water-sector workforce is due to retire within a decade. Rigs and people, not orders, set the ceiling.

The honest product verdict

Section 10 of the report asks whether QuoteAgent — Construct365's quoting app — belongs in this market, and answers no on every axis. Quotes here originate from a written specification and a bill of quantities issued by a chartered engineer, not from a site visit with a lay client; the pricing unit is rig days, metres by method and standing time, not supply-and-fit items from a firm's own price book; and 310 firms cannot fund a self-serve product at any plausible price. The report's words: there is no wedge here for this product, and establishing that on paper is cheaper than proving it through ten failed sales calls.

What the sector is, the report argues, is a good market for a directory and data business: real companies with real plant and real accounts, badly served by a SIC code that misclassifies half its register, with no free published turnover ranking anywhere in ground investigation.

Get the full report

The complete 26-page report covers the scope and misregistration analysis, the market sizing with its stated uncertainty range, the four-tier operator structure, the judgement-based composite of the ten largest operators, the AGS-era technology stack, seven documented strain points, the product-fit test, and a full sources-and-caveats section that flags every estimated figure as an estimate.

Download the SIC 43130 Sector Intelligence Report (free — no email required)