How much does external wall insulation cost in Ireland?

External Insulation Pricing Guide 2026

In 2026, external wall insulation projects typically start from €180 to €220. This turnkey standard includes scaffolding, substrate preparation, adhesive and mechanical dowelling, 100mm to 150mm Baumit EPS, embedded fibreglass mesh reinforcement, and a breathable silicone-based acrylic render topcoat.

Factors Influencing the Cost of External Wall Insulation

Final project costs depend on specific site requirements and technical factors:

• Coastal & Marine Weather Exposure: Properties close to the sea require specialized silicone-based acrylic renders (such as Baumit SilikonTop) to prevent water penetration, salt efflorescence, and algae bloom.
• High Water Window Cills: Window cills subject to high water runoff require bespoke aluminium over-sills manufactured with a special protective powder coating from Cills.ie to guarantee waterproof performance.
• Architectural Detailing & Finish: Reveal details, plinth insulation, decorative textures, and colour selection.
• Services & Pipework: Relocating external gas meter boxes, ESB service lines, and extending rainwater downpipes.

SEAI Better Energy Homes Grant Rules 2026

To qualify for the SEAI external wall insulation grant in 2026:

• The home must be built and occupied on or before 31 December 2010 (built before 2011).
• All works must be carried out by an SEAI Registered Contractor (Isotherm).
• Second Wall Measure (from 2 March 2026): Homes that previously received a grant for cavity wall insulation or drylining are now eligible to claim the full EWI grant.
• The grant (€3,000 to €8,000) is deducted directly from your final invoice by Isotherm.