Cost guide · Verified May 2026
External wall insulation cost in Ireland — typical price + SEAI grant
External wall insulation (EWI) typically costs €8,000–€18,000 in Ireland depending on dwelling type. The SEAI grant of up to €8,000 (detached) brings the net cost to €2,000–€12,000 with a typical payback of 8–15 years.
Typical cost by dwelling type
Costs include insulation board, mechanical fixings, mesh, render finish and scaffolding for a standard install. Difficult access, period detail (e.g. moulded surrounds), or premium render finishes can push costs significantly higher.
| Dwelling type | Typical gross cost | SEAI grant |
|---|---|---|
| Apartment | €4,000–€8,000 | €3,000 |
| Mid-terrace | €6,000–€10,000 | €3,500 |
| Semi-detached / End of terrace | €8,000–€14,000 | €6,000 |
| Detached | €12,000–€18,000 | €8,000 |
Worked example · 3-bed semi
Net cost after the SEAI grant
- Gross cost
- €10,000
- SEAI grant
- −€6,000
- You pay
- €4,000
Mid-range 3-bed semi at €10,000 gross, €6,000 SEAI grant for semi-detached, net €4,000. Higher-spec finishes or larger homes push the net cost up.
Payback period
EWI typically saves €600–€1,200/year in heating bills on a poorly-insulated home (D-rated or worse), with the highest savings on oil-heated homes. Payback from bill savings alone is typically 8–15 years after the grant — but EWI also enables a heat pump (which a poorly-insulated home cannot run efficiently) and adds significant resale value.
EWI is rarely worth doing for the bill savings alone — the payback is mainly justified by (a) unlocking a heat pump retrofit and (b) the resale-value uplift. If you are not planning either, attic and cavity insulation give faster payback per euro.
Common questions
- How much does external wall insulation cost in Ireland?
- External wall insulation (EWI) typically costs €8,000–€18,000 in Ireland depending on dwelling size, render finish, scaffolding requirements, and contractor. A 3-bed semi-detached usually lands at €8,000–€14,000 gross.
- How much is the SEAI external wall insulation grant?
- The SEAI EWI grant ranges from €3,000 (apartment) to €8,000 (detached house) — €6,000 for semi-detached / end of terrace and €3,500 for mid-terrace. These are 2026 rates.
- What is the payback period for external wall insulation?
- Payback for EWI is typically 8–15 years from heating bill savings of €600–€1,200/year, depending on the home's starting BER and heating system. EWI also adds significant resale value and is often a prerequisite for a heat pump.
- Is external wall insulation worth it?
- For solid-wall homes or those with a poor-performing cavity, EWI is often the single highest-impact fabric upgrade — typically eliminating 25–35% of total heat loss. The economics improve substantially when combined with a heat pump (which depends on good fabric to run efficiently).
- Can I do internal wall insulation instead?
- Yes — internal wall insulation (drylining) is cheaper per m² but loses you some internal floor area and requires moving sockets/skirtings. Internal wall grant is €1,500–€4,500 (vs €3,000–€8,000 for EWI). EWI is usually preferred for solid-wall homes; internal is better for terraced/conservation properties where external work isn't allowed.
See your exact grant amount
The navigator works out your specific grant based on dwelling type and BER. 3 minutes, no sign-up.
Run the navigatorIndicative figures based on typical Irish market averages. Costs vary by property size, age, condition, render finish, and location. Always get at least 3 quotes from SEAI-registered contractors.