Borehole water supply cost
Costs verified against BCIS Online (May 2026 release) and ONS Construction Output Price Index, April 2026. Class Q rules current to the 21 May 2025 GPDO amendment.
A domestic borehole for a rural barn typically costs £8,000 to £14,000 installed, including the borehole drill, pump, UV treatment and softener. The Private Water Supplies Regulations risk assessment is a £350-£800 local-authority charge.
Cost stack
Borehole drill (60-90 m, typical)
£3,500 - £6,500
Submersible pump and headworks
£1,400 - £2,800
UV treatment
£600 - £1,200
Softener and pressure vessel
£900 - £1,800
LA risk assessment (one-off)
£350 - £800
Annual water sample
£90 - £180
Regulatory
Private supplies serving a domestic dwelling are regulated under the Private Water Supplies Regulations and overseen by the local authority. A Regulation 9 risk assessment runs every five years. Sample frequency depends on the LA risk score.
Sources cited on this page