Air Source vs Ground Source Heat Pump - Which Should You Choose?
Both types qualify for the £7,500 BUS grant. But they differ significantly in installation cost, efficiency, and space requirements.
- £7,500 BUS grant
- £10,000-18,000 installed
- Only needs outdoor wall space
- SCOP: 3.5-4.5
- Slightly less efficient than ground source
- Performance drops in very cold weather
- £7,500 BUS grant
- SCOP: 4.0-5.0 (more consistent)
- More efficient in cold weather
- Quieter - buried system
- £20,000-35,000 installed
- Needs significant garden space
Which should you choose?
For most UK homeowners, air source is the right choice. The lower installation cost (£10,000-18,000 vs £20,000-35,000 for ground source) makes economic sense in most cases, especially after the £7,500 BUS grant.
Ground source makes sense if: you have significant garden space (typically 200-600m² for horizontal loops, or 1-2 boreholes for vertical), you plan to stay long-term and want maximum efficiency, and you can absorb the higher upfront cost.
Air source makes sense if: you have limited outdoor space beyond a wall or garden area, you want faster installation (days vs weeks for ground source), and you want the lowest possible post-grant cost.
Important disclaimer
heatpumpcompared.co.uk is editorially independent and not affiliated with any heat pump manufacturer or installer. We do not provide heating advice. Prices, specifications, SCOP ratings and grant amounts are correct as of April 2026 but are subject to change. Always commission a professional heat loss survey before purchasing a heat pump system.