Heat Pump in Ireland 2026 — Air-to-Water Cost, SEAI Grant, and the 6 vs 9 kW Question
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Air-to-water heat pump 6–9 kW: €8,500–€15,000 installed. SEAI grant €6,500 + €3,500 bonus. Net €2,000–€8,500.
Air-to-water heat pump in Ireland 2026: 6–9 kW, €8,500–€15,000 installed. SEAI grant €6,500 + potential €3,500 bonus for full-house fabric upgrade (where applicable). Net cost: €2,000–€8,500. Standard 2026 setup for new self-builds targeting BER A1. Sizing: 6 kW for a fabric-first 150 m² house (wall 0.13, roof 0.13, floor 0.13, airtightness 1–3 m³/m²·hr at 50 Pa). 9 kW for a less insulated house. Oversizing wastes money and reduces efficiency. The heat pump works best with underfloor heating (low flow temperature, 35°C) and less well with radiators (high flow temperature, 50–60°C). SEAI grant is conditional on a BER assessment after the work.
When this matters most
You're at design stage and need to specify the heat pump.
When this doesn't apply
The heat pump is commissioned.
Sources
SEAI, Heat Pump Grants 2026. https://www.seai.ie/grants/
Building Regulations 2023, TGD-L. https://www.gov.ie/
Frequently asked questions
How much does a heat pump cost in Ireland in 2026?
€8,500–€15,000 installed for a 6–9 kW air-to-water system. SEAI grant €6,500 + potential €3,500 bonus. Net cost: €2,000–€8,500.
What size heat pump do I need for a 150 m² house?
6 kW for a fabric-first house (wall 0.13, roof 0.13, airtightness 1–3). 9 kW for a less insulated house. Engineer sizes based on heat load calculation.
What is the SEAI heat pump grant?
€6,500 for an air-to-water heat pump. Plus €3,500 bonus for a full-house fabric upgrade (where applicable). Subject to BER assessment after the work.
When this matters most
You're at design stage and need to specify the heat pump.
When this doesn't apply
The heat pump is commissioned.
Where to go next
Next decision
The next step in your build sequence.
Branch into
Adjacent decisions at the same stage.
- Battery Storage in Ireland 2026 — Cost, Payback, and When to Skip It →
- Biomass Boiler in Ireland — Wood Pellet Stove, Cost, SEAI Grant, and When It Beats a Heat Pump →
- District Heating in Ireland — Where It Exists, the Connection Cost, and When It Works →
- Ground Source Heat Pump in Ireland — Borehole Cost, When It's Worth the Premium →
- Solar Thermal in Ireland — Hot Water from the Sun, When It Pays Back, and the Alternatives →
Watch out for
Common mistakes, hidden costs, gotchas.
- Battery Storage in Ireland 2026 — Cost, Payback, and When to Skip It →
- Biomass Boiler in Ireland — Wood Pellet Stove, Cost, SEAI Grant, and When It Beats a Heat Pump →
- District Heating in Ireland — Where It Exists, the Connection Cost, and When It Works →
- Ground Source Heat Pump in Ireland — Borehole Cost, When It's Worth the Premium →
- SEAI Heat Pump Grant 2026 — €6,500 + €3,500 Bonus, Eligibility, and the BER Trap →
- MVHR in Ireland — Mechanical Ventilation with Heat Recovery, Cost, and Why You Need It →
- Radiators vs Underfloor Heating in Ireland — Cost, Comfort, and Heat Pump Pairing →
- Solar PV in Ireland 2026 — 6 kWp Cost, Payback, and the SEAI Grant →
- Underfloor Heating in Ireland — Cost, Floor Build-up, and the Heat Pump Pairing →
Compare with
Alternative approaches worth knowing.