BER A1 Setup in Ireland 2026 — Heat Pump, MVHR, Solar PV, and the Numbers

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).

TL;DR

• BER A1 standard setup in Ireland 2026: 6 kW heat pump + MVHR + 6 kWp solar PV + airtightness 1–2 m³/m²·hr + wall 0.13.

• Total system cost: €18,000–€35,000 installed before grants. After SEAI grants (where applicable): €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.

When this matters most

You're at design stage targeting BER A1.

When this doesn't apply

You're targeting a lower BER.

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.

Sources

SEAI, BER and DEAP guidance. https://www.seai.ie/