Ground Source Heat Pumps - Complete 2026 Guide

How ground source heat pumps work

Ground source heat pumps extract heat from the ground using a buried loop of pipe filled with a mixture of water and antifreeze. The ground temperature below 1-2 metres stays relatively constant at 8-12°C year-round in the UK. This stable temperature source means ground source heat pumps typically achieve higher SCOP ratings (4.0-5.0) than air source (3.5-4.5).

Horizontal loops vs vertical boreholes

Horizontal loops are buried at 1-2 metres depth across a large area. They're cheaper than boreholes but require significant garden space - typically 200-600m² depending on property size. Not suitable for most urban gardens.

Vertical boreholes are drilled 50-150 metres deep. They need less surface area but cost significantly more (£10,000-20,000 for the borehole drilling alone). Suitable for properties with limited garden space but no surface parking restrictions.

Installation costs

Ground source installation costs significantly more than air source:

When does ground source make sense?

Ground source is worth considering when:

• You have adequate land for horizontal loops or planning permission for boreholes
• You want maximum efficiency and plan to stay long-term (15+ years)
• Noise is a concern (ground source outdoor units are much quieter)
• You have a large property with high heating demand where efficiency gains are significant

For most UK homeowners, air source heat pumps offer better value. Ground source suits larger rural properties and those prioritising maximum efficiency.