Gretton Site Investigations Ltd · Company 08887344 · Trading heritage since 2005
Active, accounts up to date·subcontractor·Head office Market Harborough
GSI Drilling, also known as Gretton Site Investigations Ltd, are leading UK borehole drillers with extensive experience in ground source heat systems, geothermal boreholes, soakaways, and dewatering. They pride themselves on their rapid borehole drilling services, utilizing multiple rigs to ensure minimal disruption and efficient project completion. With a team of experts specializing in drilling water boreholes and boreholes for ground source heat pumps for both commercial and domestic clients, GSI Drilling has successfully completed thousands of projects across the UK over their 19 years of operation.
Their expertise covers a wide range of geologies and ground conditions, making them capable of handling diverse projects from single water boreholes in gardens to large-scale ground source heat pump installations. The company emphasizes a client-focused approach, offering a "no water, no charge" guarantee, a 3-year works guarantee, and free, no-obligation quotes. They are committed to providing reliable water sources and efficient dewatering services to keep construction projects on track.
GSI Drilling is a proud member of the GSHPA (Ground Source Heat Pump Association) and highlights their commitment to quality and customer satisfaction through testimonials and a strong service guarantee. They are equipped with 11 drilling rigs and adept site management to ensure swift and effective service delivery, making them a trusted choice for businesses and homeowners alike seeking professional drilling solutions.
The client required a substantial pond on their land and used GSI to drill a borehole and install a pump to access water from an aquifer. After 100m of drilling, they struck water and achieved a flow of around 20,000 litres a day, fulfilling their vision for the pond.
Client · National Library of Wales
GSI delivered for the client under unbelievable time constraints and short notice, sinking a 53m borehole to provide crystal clear spring water. The client would not hesitate to recommend the company.
GSI drilled a private well behind the client's house, leaving everything clean and tidy. The client highly recommends their work for anyone looking to drill a well.
Another company started this borehole project 14 months prior, with many failed attempts and significant cost. GSI was brought in to drill the borehole and was a pleasure to deal with.
On a friend's recommendation, GSI drilled a water borehole for irrigation and domestic use. They were the only company that could finish the job from geology to connecting to the existing water system.
This profile was compiled from public records. Claim it to add the things buyers ask for:
GSI Drilling are UK borehole drilling specialists for ground source heat systems, geothermal boreholes, soakaways and dewatering. Expert drillers for commercial or domestic use. Their listed services include Piling, Drainage, Groundworks and Heating & ventilation.
GSI Drilling is registered at 29 Main Street, Ashley, Market Harborough, LE16 8HG, in East Midlands.
GSI Drilling states that it works across Nationwide.
Accounts filed for the year to 2025 report 4 employees, which places the company in the 1-9 employees band.
GSI Drilling does not disclose turnover: UK small-company accounts are not required to. Based on headcount and trade debtors in its filed accounts, turnover is likely to fall between £370k and £980k. This is an estimate, not a filed figure.
Companies House lists GSI Drilling as active, with accounts most recently made up to 2025-03-31.
GSI Drilling displays GSHPA Member 2023/24 on its website.
GSI Drilling works in Residential, Commercial, Infrastructure and Energy.
GSI Drilling was incorporated on 2014-02-11, though the company says it has traded since 2005.
Track budgets, committed costs, invoices and profitability in one place, so cost issues show up before they turn into margin surprises.