Planning Permission Ireland

A-Rated ICF Self-Build in Ireland — A 210 m² Wicklow Build, the Numbers and the Gotchas

Last updated 30/6/2026 · Reviewed 30/6/2026
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A-rated ICF on a slope (Co. Wicklow, 210 m², 2024): €610,000 build, main contractor. Site works doubled the original 10% allowance.

A-rated ICF on a slope in Co. Wicklow: 210 m², finished 2024, main contractor. Build cost: €610,000 (€2,900/m²). Site: 1.5 acres, sloped (3 m across the footprint), rural housing local needs. Build: ICF walls, slate roof, MVHR, 9 kW air-to-water heat pump, 6 kWp solar PV, BER A1. Gotchas: site-specific cost (slope, long connection runs, treatment system, retaining walls) doubled the original 10% allowance — €80,000 on site works alone. The owners underestimated the cost of the slope. The engineer specified stepped foundations and a retaining wall that added €25,000 to the foundation cost. Outcome: finished in 14 months. BER A1 confirmed. The owners credit the success to: a quantity surveyor who caught the slope cost early, a main contractor with two recent ICF builds, and a 15% contingency (which absorbed the slope overrun).

TL;DR

  • A-rated ICF on a slope (Co. Wicklow, 210 m², 2024): €610,000 build, main contractor. Build cost €2,900/m².

  • Gotchas: site-specific cost (slope, long connection runs) doubled the original 10% allowance. €80,000 on site works alone.

  • Outcome: BER A1, 9 kW heat pump, 6 kWp solar PV. Finished in 14 months. Sloped site drove the cost.

When this matters most

You're researching case studies for a sloped ICF build.

When this doesn't apply

You've already started your build.

Frequently asked questions

How much did a 210 m² ICF build cost in Wicklow in 2024?

€610,000 build, main contractor. Build cost €2,900/m². Plus site works (€80,000), fees, and VAT: total project cost €800,000–€850,000. BER A1.

What were the gotchas on this build?

Site-specific cost (slope, long connection runs) doubled the original 10% allowance. €80,000 on site works. The engineer specified stepped foundations and a retaining wall that added €25,000 to the foundation cost.

How long did the build take?

14 months on site. The slope added 2 months to the foundation phase. ICF walls were fast once the foundation was done.

Sources

SCSI, Construction Cost Database 2024. https://www.scsi.ie/

Frequently asked questions

How much did a 210 m² ICF build cost in Wicklow in 2024?

€610,000 build, main contractor. Build cost €2,900/m². Plus site works (€80,000), fees, and VAT: total project cost €800,000–€850,000. BER A1.

What were the gotchas on this build?

Site-specific cost (slope, long connection runs) doubled the original 10% allowance. €80,000 on site works. The engineer specified stepped foundations and a retaining wall that added €25,000 to the foundation cost.

How long did the build take?

14 months on site. The slope added 2 months to the foundation phase. ICF walls were fast once the foundation was done.

When this matters most

You're researching case studies for a sloped ICF build.

When this doesn't apply

You've already started your build.

Where to go next

Watch out for

Common mistakes, hidden costs, gotchas.