Heat Pump in Ireland 2026 — Air-to-Water Cost, SEAI Grant, and the 6 vs 9 kW Question

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.

TL;DR

• 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.

• Net cost after grant: €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). 9 kW for a less insulated house. Oversize wastes money.

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.

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.

Sources

SEAI, Heat Pump Grants 2026. https://www.seai.ie/grants/

Building Regulations 2023, TGD-L. https://www.gov.ie/