Insulation is one of the most cost-effective home upgrades you can make. SEAI grants cover a large part of the cost, particularly for cavity wall and external wall insulation where labour costs are high.

Attic insulation grants

Dwelling typeNon-FTBFirst-time buyer
Detached€2,000€2,500
Semi-detached / end-terrace€1,500€1,900
Mid-terrace€1,400€1,800
Apartment€1,100€1,400
Source: SEAI, 12 June 2026

Attic insulation typically costs €800–1,500 installed for a semi-detached home. With the €1,500 grant, the net cost is often under €500, making it one of the best-value upgrades available.

Cavity wall insulation grants

Dwelling typeStandardWelfare/medical card
Detached€1,800€2,300
Semi-detached / end-terrace€1,300€1,700
Mid-terrace€850€1,100
Apartment€700€900

Internal wall insulation (dry-lining)

Internal dry-lining is used where cavity fill isn’t possible (solid walls, timber frame, etc.).

Dwelling typeGrant
Detached€4,500
Semi-detached / end-terrace€3,500
Mid-terrace€2,000
Apartment€1,500

External wall insulation (EWI) grants

External wall insulation (wrapping the outside of the house) is the most comprehensive solution for solid-wall homes. It’s also the most expensive, with installed costs often running to €15,000–25,000 for a detached home.

Dwelling typeGrant
Detached€8,000
Semi-detached / end-terrace€6,000
Mid-terrace€3,500
Apartment€3,000

Rafter and floor insulation (One Stop Shop only)

Rafter insulation (for attics with limited headroom or converted attics) and floor insulation are only available through the One Stop Shop scheme.

MeasureDetached / semiMid-terraceApartment
Rafter insulation€3,000€2,000€1,500
Floor insulation€3,500€3,500€3,500

What insulation should I prioritise?

If your home has an accessible attic, attic insulation is almost always the first upgrade to do: lowest cost, highest grant percentage, and quickest payback (often under 2 years).

After attic insulation, cavity wall insulation (if your walls have an accessible cavity) is the next best value. External wall insulation is the most impactful but also the most expensive, and it makes most sense as part of a deeper retrofit.

See our insulation guide for more detail on what’s involved.