Air Source Heat Pump Cost in Scotland 2026
Real ASHP install costs in Scotland, factoring in HES grant + loan. What you actually pay out of pocket.
Quick answer
An air source heat pump (ASHP) for a typical 4-bed Scottish home costs £12,000–£18,000 fully installed in 2026. With the Home Energy Scotland grant (£7,500) and loan (up to £7,500) stacked, out-of-pocket lands £0–£3,000 for most households.
What "fully installed" includes
A complete ASHP package isn't just the outdoor unit. Typical Ecoaim ASHP quote covers:
- 8–14kW Mitsubishi Ecodan or Daikin Altherma outdoor unit
- Indoor hydrobox + controls
- New 200–300L hot water cylinder (most existing cylinders are too small)
- Radiator sizing assessment + replacements where needed (older microbore radiators almost always need upgrading)
- Pipework upgrades, system balancing
- MCS heat-loss calculation + design
- DNO notification (heat pumps over a certain rating need G99)
- Commissioning + handover pack
- HES grant + loan application paperwork
The single biggest cost driver is radiator upgrade scope. Properties with newer (post-2010) modern radiators rated for low flow temperatures often need none; older properties with microbore systems can need 4–8 rads upgraded.
Out-of-pocket — the real number
For a typical Bathgate or Linlithgow 4-bed home with mid-range radiator work:
- Install cost: £15,500
- HES grant: £7,500
- HES interest-free loan: £7,500 (over 10 years, £62.50/month)
- Out-of-pocket cash: £500
For rural properties (Carnwath, Forth, parts of West Lothian):
- Install cost: £15,500
- HES grant (rural uplift): £9,000
- HES loan: £6,500
- Out-of-pocket cash: £0
- (Often the grant alone covers it plus a bit of contingency)
Running cost — heat pump vs gas vs oil
For a typical Scottish 4-bed at current 2026 prices:
| Heating fuel | Annual cost |
|---|---|
| Mains gas (boiler) | £1,400 |
| LPG (boiler) | £2,200 |
| Oil (boiler) | £1,800 |
| Direct electric (storage heaters) | £2,400 |
| ASHP (SCOP 3.2) | £950 |
ASHP wins on running cost for every fuel except subsidised mains gas in 2026 — and the gap widens as gas prices rise and electric tariffs adjust.
Pair ASHP with solar PV and you decarbonise heating at the same time as electrifying it.
SCOP — the number that matters
SCOP (Seasonal Coefficient of Performance) tells you the average ASHP efficiency across a Scottish heating season. Modern units deliver:
- 3.0–3.2 for older insulation-poor homes with high flow temperatures
- 3.4–3.8 for well-insulated homes with low flow temperatures
- 4.0+ for new-build homes with underfloor heating
We model your specific SCOP at quote time using the MCS heat-loss calculation. If the modelling shows SCOP < 2.8, we're transparent — ASHP may not save you money in your specific case until other insulation improvements are made.
When ASHP doesn't work (yet)
- Heat loss > 14kW — large old draughty stone houses. Address insulation first.
- Radiators all microbore + cement walls — radiator replacement cost can balloon
- Listed buildings with planning constraints — MCS 020 noise rules + heritage rules can clash
- Flat owners with shared roof/wall — outdoor unit placement is difficult
Choosing an ASHP installer
- MCS certified for ASHP (mandatory for HES grant + loan)
- MCS 020 fluent (noise emissions rules)
- Heat-loss calculation included as standard (not £200 extra)
- Radiator scope quoted explicitly (not "from £X")
- Workmanship warranty 5+ years (we offer 5 yrs; some offer 10)
- Manufacturer training (Mitsubishi MELCloud, Daikin Cloud Control — installer logins matter)
Typical timeline
- Day 0: Quote sent
- Day 7: HES grant + loan application submitted
- Day 35–49: HES approval
- Day 56: Materials ordered, install scheduled
- Day 70–77: Install (2–4 days on site)
- Day 84: MCS certificate issued, HES sign-off
- Day 90: Grant + loan funds released
Next step
Free heat-loss assessment + fixed quote in 24 hours. We handle HES grant + loan applications in-house. Call 03330 384 380 or use our online form.
Call 03330 384 380 or get a quote online — survey + quote within 24 hours.
