Cavity wall insulation
This is usually the first wall route people hope for because it is the least disruptive when the home is suitable. But it only applies where the wall construction actually supports it.
SEAI wall guide
Wall insulation grant Ireland: the SEAI routes explained
Wall insulation is one of the biggest sources of confusion for Irish homeowners because there is no single wall route. When people search for wall insulation grant Ireland, what really matters is whether the home suits cavity wall insulation, internal insulation or external insulation.
Wall type changes everything: cavity, internal and external routes can differ hugely in cost and disruption.
Cavity walls often look simplest: but only when the home actually suits that route.
Use the checker first: it helps narrow down likely grant support before you start taking follow-up calls.
Internal wall insulation
Internal insulation can be a very different proposition. It may suit certain homes, but it generally involves more interior disruption and should never be treated as the same thing as cavity fill.
External wall insulation
External wrap can transform the building fabric, but it is usually one of the bigger wall insulation routes in terms of scope and homeowner cost.
Why the checker helps
Our checker does not replace an installer survey, but it helps homeowners understand the likely grant path by home type before they commit to conversations.
Official March 2026 wall grant facts
Cavity wall grants
The current SEAI cavity wall grant is €1,800 detached, €1,300 semi-detached, €850 mid-terrace and €700 apartment. Higher cavity grants also apply in some qualifying welfare cases.
Internal wall grants
The current internal wall insulation grant is €4,500 detached, €3,500 semi-detached, €2,000 mid-terrace and €1,500 apartment.
External wall grants
The current external wall insulation grant is €8,000 detached, €6,000 semi-detached, €3,500 mid-terrace and €3,000 apartment.
SEAI median costs
Latest SEAI medians are about €2,250 / €1,500 / €1,100 / €903 for cavity, €9,000 / €10,532 / €6,530 / €4,095 for internal, and €24,000 / €23,333 / €13,500 / €15,750 for external. That is why wall type matters so much before anyone talks about cost to the homeowner.
What affects the likely wall route
- Construction type: cavity and solid wall homes behave very differently.
- House type: detached, semi-detached, terrace and apartment homes do not all present the same wall area or access conditions.
- Existing condition: the installer still needs to confirm the wall build-up on site.
- Disruption tolerance: internal and external solutions are very different in practice.
What homeowners often get wrong
Many people hear "wall insulation grant" and assume one number covers all wall jobs. That is usually the wrong way to think about it. With walls, the specific wall type is often more important than almost anything else.
Check likely wall insulation support the practical way
Use the checker if you want to see likely grant support and typical homeowner cost by Eircode, house type and build year before deciding whether you want local SEAI-registered installers to contact you.
Frequently asked questions
Is cavity wall insulation the same as internal or external insulation?
No. They are different routes, with very different cost profiles and disruption levels, so they should not be treated as one blended wall figure.
Why does wall insulation guidance vary so much by house?
Because wall construction varies. The correct grant path depends on the building fabric, not just the fact that the homeowner wants warmer walls.
Where do I confirm the official SEAI wall grant?
Always check the live SEAI wall insulation page for the current rules and values before making a decision.