Which is cheaper — air source or ground source heat pump?

Air source heat pumps are much cheaper to buy and install: £11,000–£16,000 (or £3,500–£8,500 after the £7,500 grant) for a 3-bed home, versus £19,000–£35,000 for ground source. Over 20 years, ground source's lower running costs can narrow the gap, but for most homes the air source system has far better payback in the UK.

Is a ground source heat pump more efficient than air source?

Yes — ground source heat pumps typically achieve a SCOP of 3.5–4.5 versus 3–4 for air source, because ground temperature stays stable year-round. That means lower running costs for the same heat output. But the savings are modest (roughly £150–£300 a year for a typical home) and take many years to offset the higher install cost.

How much space does a ground source heat pump need?

A horizontal ground loop needs a large garden (roughly 1.5–2 times the floor area of the property, or about 600–1,000m² of land for a typical home). A vertical borehole needs far less surface area but costs more to drill — typically £4,000–£8,000 for the drilling alone. Air source only needs room for one outdoor unit (commonly about 1m²).

Are ground source heat pumps louder than air source?

No — ground source heat pumps are generally quieter because the heat source is underground and the outdoor ground loop makes no noise. Air source units have an outdoor fan and compressor that typically run at 37–52 dB. If noise near a boundary line is a concern, ground source avoids it entirely.

Can I get the £7,500 grant for a ground source heat pump?

Yes — the Boiler Upgrade Scheme pays £7,500 toward both air source and ground source heat pumps (ground source was historically capped at £6,000 but the flat £7,500 rate now applies to both). The grant still covers a far smaller share of ground source's higher install cost, which is why air source is the more popular choice.

Which is cheaper — air source or ground source heat pump?

Air source heat pumps are much cheaper to buy and install: £11,000–£16,000 (or £3,500–£8,500 after the £7,500 grant) for a 3-bed home, versus £19,000–£35,000 for ground source. Over 20 years, ground source's lower running costs can narrow the gap, but for most homes the air source system has far better payback in the UK.

Is a ground source heat pump more efficient than air source?

Yes — ground source heat pumps typically achieve a SCOP of 3.5–4.5 versus 3–4 for air source, because ground temperature stays stable year-round. That means lower running costs for the same heat output. But the savings are modest (roughly £150–£300 a year for a typical home) and take many years to offset the higher install cost.

How much space does a ground source heat pump need?

A horizontal ground loop needs a large garden (roughly 1.5–2 times the floor area of the property, or about 600–1,000m² of land for a typical home). A vertical borehole needs far less surface area but costs more to drill — typically £4,000–£8,000 for the drilling alone. Air source only needs room for one outdoor unit (commonly about 1m²).

Are ground source heat pumps louder than air source?

No — ground source heat pumps are generally quieter because the heat source is underground and the outdoor ground loop makes no noise. Air source units have an outdoor fan and compressor that typically run at 37–52 dB. If noise near a boundary line is a concern, ground source avoids it entirely.

Can I get the £7,500 grant for a ground source heat pump?

Yes — the Boiler Upgrade Scheme pays £7,500 toward both air source and ground source heat pumps (ground source was historically capped at £6,000 but the flat £7,500 rate now applies to both). The grant still covers a far smaller share of ground source's higher install cost, which is why air source is the more popular choice.

Air Source vs Ground Source Heat Pump — Which Is Right for You?

Cost, efficiency, space, noise & running costs compared for UK homes in 2026.

Air source is the right choice for most UK homes. It costs £11,000–£16,000 installed (£3,500–£8,500 after the £7,500 grant) versus £19,000–£35,000 for ground source. Ground source is more efficient (SCOP 3.5–4.5 vs 3–4) and quieter, but the extra install cost takes many years to claw back — it only makes sense if you have a large garden and plan to stay put for 10+ years.

The Big 5: 1 of 5

Cost & Price — The Big Difference Is Upfront

Purchase and installation dominate the decision, not running cost. Air source needs just an outdoor unit; ground source requires digging horizontal ground loops across a large garden or drilling a vertical borehole. That civil-works cost is the reason ground source runs 1.6–2x the price of air source.

##	Air source	Ground source
Typical install (3-bed)	£11,000 – £16,000	£19,000 – £35,000
After the £7,500 grant	£3,500 – £8,500	£11,500 – £27,500
Extra groundwork (loop/borehole)	None	Horizontal £3k–£6k / borehole £4k–£8k

Ground-source groundwork figures are added on top of the base system cost for a typical 3-bed property.

The Big 5: 2 of 5

Side-by-Side Spec Comparison

Attribute	Air source	Ground source
Install cost (3-bed)	£11,000 – £16,000✓	£19,000 – £35,000
Cost after £7,500 grant	£3,500 – £8,500✓	£11,500 – £27,500
Efficiency (SCOP)	3.0 – 4.0	3.5 – 4.5✓
Running cost / year	£900 – £1,250	£750 – £1,050✓
Space required	Outdoor unit ~1m²✓	Horizontal loop 600–1000m² or a borehole
Noise	37 – 52 dB outdoor	Near-silent (heat source underground)✓
Lifespan	15 – 20 years	25+ years✓
Garden / land needed	No✓	Large area or drilling

Air source wins 4 of 8 categories; ground source wins 4 of 8 — it genuinely comes down to budget, land and planning horizon.

The Big 5: 3 of 5

Versus & Comparisons — When the Efficiency Gap Matters

The core trade-off is efficiency vs upfront cost. Ground source’s higher SCOP delivers roughly £150–£300 less per year in running costs for a typical 3-bed home. But that saving must be weighed against the £8,000–£19,000 higher install cost. At even £250/year in savings, it takes 30–75 yearsto break even — far beyond the lifespan of most homeowners’ stay in one property.

The key insight:

Ground source only makes financial sense if you have a large garden for a horizontal loop (keeps the groundwork cost down), current oil/LPG/electric heating(so you’re saving against an expensive baseline), and plan to stay 10+ years. Otherwise the £7,500 grant makes air source the clear value winner.

The Big 5: 4 of 5

Who Each System Is For

Ground source is for you if…

✅ You own enough land for a horizontal loop (or have budget for a borehole).
✅ You’re replacing an expensive oil or electric system and want the lowest possible running cost.
✅ You plan to stay in the property for 10+ years and value a 25-year lifespan.
✅ Noise is a real concern at your boundary (ground source is near-silent).

Air source is for everyone else — which is most people

✅ You want the lowest upfront cost, especially with the £7,500 grant.
✅ Limited garden space, or renting, or you don’t want trenching/drilling on the property.
✅ You may move within 5–10 years and want the investment de-risked.
✅ You want a simpler, quicker install — typically 2–5 days versus weeks of groundwork.

The Big 5: 5 of 5

Verdict

The bottom line:

Buy an air source heat pump unless you specifically have the land, the budget and the long-term horizon to justify ground source's efficiency edge. For a typical UK home, air source after the £7,500 grant is a fraction of ground source's cost and quietly delivers most of the running-cost benefit. Compare the 10 best air source heat pumps or see the running costs vs gas.

More on heat pumps

The 10 best heat pumps in the UK, compared →

Heat pump cost UK 2026 — full breakdown →

Heat pump running costs vs a gas boiler →

£7,500 Boiler Upgrade Scheme grant →

Find an MCS-certified heat pump installer →

Not sure which type? Get 3 free quotes for both

MCS-certified installers will quote both air source and (where suitable) ground source options for your property.

Before you pay a penny

You could be £7,500 better off

The government’s Boiler Upgrade Scheme gives every eligible homeowner £7,500 toward a new heat pump — paid straight to your installer, so it comes off your quote. No income means test and it covers most of the cost of a typical air source heat pump.

Check your grant eligibility →

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Air vs Ground Source — Frequently Asked Questions

FAQ

Air vs ground source heat pump FAQs

Which is cheaper — air source or ground source heat pump?: Air source heat pumps are much cheaper to buy and install: £11,000–£16,000 (or £3,500–£8,500 after the £7,500 grant) for a 3-bed home, versus £19,000–£35,000 for ground source. Over 20 years, ground source's lower running costs can narrow the gap, but for most homes the air source system has far better payback in the UK.
Is a ground source heat pump more efficient than air source?: Yes — ground source heat pumps typically achieve a SCOP of 3.5–4.5 versus 3–4 for air source, because ground temperature stays stable year-round. That means lower running costs for the same heat output. But the savings are modest (roughly £150–£300 a year for a typical home) and take many years to offset the higher install cost.
How much space does a ground source heat pump need?: A horizontal ground loop needs a large garden (roughly 1.5–2 times the floor area of the property, or about 600–1,000m² of land for a typical home). A vertical borehole needs far less surface area but costs more to drill — typically £4,000–£8,000 for the drilling alone. Air source only needs room for one outdoor unit (commonly about 1m²).
Are ground source heat pumps louder than air source?: No — ground source heat pumps are generally quieter because the heat source is underground and the outdoor ground loop makes no noise. Air source units have an outdoor fan and compressor that typically run at 37–52 dB. If noise near a boundary line is a concern, ground source avoids it entirely.
Can I get the £7,500 grant for a ground source heat pump?: Yes — the Boiler Upgrade Scheme pays £7,500 toward both air source and ground source heat pumps (ground source was historically capped at £6,000 but the flat £7,500 rate now applies to both). The grant still covers a far smaller share of ground source's higher install cost, which is why air source is the more popular choice.

Sources & cited data

Boiler Upgrade Scheme — GOV.UK / Energy Security & Net Zero — https://www.gov.uk/apply-boiler-upgrade-scheme
Heat Pumps (air & ground source) — Energy Saving Trust — https://energysavingtrust.org.uk/advice/heat-pumps/
MCS Heat Pump Installation Standards — https://mcscertified.com/products-and-schemes/heat-pumps/

SCOP and lifespan figures are from MCS-certified datasheets and installer guides. Cost ranges are 2026 typical figures and should be confirmed with a site-specific quote.