The service
External wall insulation in Ireland
Insulation on the outside of the walls, finished in render. SEAI pays €6,000 for a semi-D and €8,000 for a detached house. What it is, what it costs and what the grant needs.
Free, no obligation. One SEAI-registered contractor prices it, not five.
- €6,000SEAI grant, semi-D
- €6,000SEAI grant for a semi-D
- 150 mmmost homes can add without planning
External wall insulation is insulation board fixed to the outside of your walls and finished with a mesh-reinforced render. SEAI pays €8,000 for a detached house, €6,000 for a semi-D, €3,500 for a mid-terrace and €3,000 for an apartment, and its median cost for a semi-D in the first half of 2026 was €23,219.
In Ireland it's also called house wrap or exterior wall insulation, and SEAI names the grant "External wall insulation (the wrap)".
What is external wall insulation?
SEAI describes it as insulation such as mineral wool or expanded polystyrene (EPS) slabs fixed to the outside of the wall, covered with a special render for weather resistance, with a steel or fibreglass mesh in the render for strength and impact resistance (SEAI Homeowner's Guide to Wall Insulation). NSAI calls the same thing ETICS, External Thermal Insulation Composite Systems (NSAI).
SEAI says a home loses 20–30% of its heat through the external walls if they aren't properly insulated. Because the insulation goes on the outside, the rooms stay the same size and the house gets a new finish.
How much does external wall insulation cost in Ireland?
SEAI's median for a semi-D or end of terrace was €23,219 from January to June 2026, about €17,219 after the €6,000 grant. A mid-terrace was €14,000, about €10,500 after the grant.
| Home type | SEAI median cost, Jan–Jun 2026 | SEAI grant | Left after the grant |
|---|---|---|---|
| Detached house | €26,500 | €8,000 | €18,500 |
| Semi-D or end of terrace | €23,219 | €6,000 | €17,219 |
| Mid-terrace | €14,000 | €3,500 | €10,500 |
| Apartment | €11,300* | €3,000 | not shown* |
SEAI's own median costs from 23,412 grant-funded upgrades; VAT isn't stated. *SEAI says its apartment figure comes from five completed homes.
Per m² prices, worked examples and what pushes a quote up are in the cost guide.
How is the wall built up?
- Insulation board. EPS or mineral wool slabs, fixed to the wall. SEAI's scheme needs the finished wall to reach a U-value of 0.27 W/m²K, so the board thickness comes from a U-value calculation for your wall.
- Basecoat with mesh. A polymer-modified cement basecoat is 3 to 6 mm thick, or 20 to 30 mm for a traditional render basecoat, with the mesh bedded in it (energyefficiency.ie).
- Finish coat. The top coat, 1 to 10 mm thick depending on the finish. See finishes for render, colour and brick-effect options.
- Reveals, sills and roof line. NSAI says the reveals, heads and cills around windows and doors must all be insulated, old cills may be replaced with certified over-cills, and the roof line may need altering for the thicker wall.
Which walls can take it?
NSAI lists these as suitable: rendered masonry, solid or hollow block, solid concrete or brick, and brick-faced or rendered cavity walls where the right measures are taken. It lists timber frame, steel frame and timber-clad walls as unsuitable (NSAI leaflet).
That's why the wrap matters most for solid and hollow block houses: they can't be cavity-filled, so external or internal insulation are their only wall grants. See how common those walls are in your county, or compare external, internal and cavity.
What the SEAI grant needs
- You own the home, it was built and occupied before 2011, and it has an 11-digit MPRN.
- No wall insulation grant on that MPRN before. A home that had a cavity or internal grant can still apply for the wrap as a second wall measure.
- An SEAI-registered contractor, and the grant offer before any work starts.
- Every external wall fully insulated. SEAI doesn't fund partial insulation.
- If more than 25% of the home's surface area is altered, Building Regulations apply: the home must reach a B2 BER, or have heating and attic insulation that meet the Building Regulation standard.
- A post-works BER by a registered BER assessor before the grant is paid (SEAI gives €50 towards it), all within 8 months of the grant offer.
Do you need planning permission?
Usually not, since 27 July 2026. Class 63 of S.I. No. 341 of 2026 makes external wall insulation to a house exempted development if it's no more than 150 mm thick on the front, rear or gable, doesn't encroach on a public road, and doesn't change the look so that it's out of character with the house and its neighbours (S.I. No. 341 of 2026). Planning, in full.
How to check the contractor and the system
SEAI says the contractor must use an NSAI Agrément certified product or equivalent, must be NSAI registered to install it, and must be on SEAI's register, or you can't get the grant (SEAI). NSAI runs a registered installer scheme for external insulation, which assesses that the installer's workmanship complies with the Agrément certificate (NSAI). Ask for the certificate number and check it on nsai.ie.
FAQ
Questions people ask
What is external wall insulation?
Insulation board (mineral wool or EPS) fixed to the outside of the walls and covered with a mesh-reinforced render. In Ireland it's also called house wrap or exterior wall insulation.
How much does external wall insulation cost in Ireland?
SEAI's median from January to June 2026 was €14,000 for a mid-terrace, €23,219 for a semi-D and €26,500 for a detached house, before the grant.
How much is the external wall insulation grant?
€8,000 detached, €6,000 semi-D or end of terrace, €3,500 mid-terrace and €3,000 apartment, fixed by SEAI.
Can external insulation go on a timber frame house?
NSAI's homeowner leaflet lists timber frame, steel frame and timber-clad walls as unsuitable for external insulation systems.
What U-value does the grant need?
0.27 W/m²K. SEAI says U-value calculations must be done in every case to show the wall meets it.
Is exterior wall insulation the same as external wall insulation?
Yes. Exterior wall insulation, external insulation, ETICS and house wrap all mean the same job in Ireland.
Your grant
Your house wrap grant in 3 taps
Tap your home type, when it was built and any earlier wall grant. Your SEAI grant shows as you go. Then leave your number and one SEAI-registered external insulation contractor who covers your area rings you with a price.