BER A1 Setup in Ireland 2026 — Heat Pump, MVHR, Solar PV, and the Numbers
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BER A1 standard setup: 6 kW heat pump + MVHR + 6 kWp solar PV + airtightness 1–2 m³/m²·hr + wall 0.13.
BER A1 standard setup in Ireland 2026: 6 kW air-to-water heat pump + MVHR (250–350 m³/h) + 6 kWp solar PV + airtightness 1–2 m³/m²·hr at 50 Pa + wall U-value 0.13 W/m²K + roof 0.13 + floor 0.13. Total system cost: €18,000–€35,000 installed before grants. After SEAI grants (where applicable for retrofit): €12,000–€25,000. Airtightness is the most under-achieved element. Most BER A1 failures are at 3 m³/m²·hr — the design target, not the Part L minimum. The interim blower door test at first-fix (before plastering) catches the cheap fixes. Most Irish self-builds that achieve BER A1 do so with timber frame or ICF (cleaner airtightness than blockwork).
When this matters most
You're at design stage targeting BER A1.
When this doesn't apply
You're targeting a lower BER.
Sources
SEAI, BER and DEAP guidance. https://www.seai.ie/
Frequently asked questions
What system do I need for BER A1?
6 kW heat pump + MVHR + 6 kWp solar PV + airtightness 1–2 m³/m²·hr + wall 0.13 W/m²K. Total: €18,000–€35,000 installed.
What is the most common BER A1 failure?
Airtightness. Most BER A1 failures are at 3 m³/m²·hr — the design target, not the Part L minimum. The interim blower door test at first-fix catches the cheap fixes.
Can a blockwork house achieve BER A1?
Yes, but harder than timber frame or ICF. Blockwork needs careful detailing for airtightness, and the render needs to be airtight. Timber frame and ICF make A1 easier.
When this matters most
You're at design stage targeting BER A1.
When this doesn't apply
You're targeting a lower BER.
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 →
- Heat Pump in Ireland 2026 — Air-to-Water Cost, SEAI Grant, and the 6 vs 9 kW Question →
- 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.