How much does external wall insulation cost in Ireland?
External wall insulation is the most expensive fabric upgrade and the most effective. The honest answer to what it costs is that it depends on measurable things — wall area, the state of the existing render, scaffolding access and what happens at the roof edge. Here is what actually moves the number.
What you are paying for
External wall insulation is not one product. It is a certified system: insulation board mechanically fixed and bonded to the wall, a reinforcing mesh embedded in basecoat, and a through-coloured render finish. Every component is tested together, and mixing parts from different systems voids the certification and the guarantee.
Cost is usually quoted per square metre of wall area, not per square metre of floor area. Those are very different numbers. A modest three-bed semi can carry {{PRICE_VERIFY}} m² of external wall, and a detached bungalow considerably more because it has four exposed elevations rather than two.
Our own current rate is {{PRICE_VERIFY}} per square metre for a standard system, which includes supply, installation and finish to a completed render.
The five things that move the price
- Wall area. The single largest factor, and the reason a quote without a measured survey is guesswork. Detached houses cost far more than mid-terrace because they have more wall.
- Access and scaffolding. A two-storey house needs scaffolding; a bungalow often does not. Restricted side passages, overhead cables and boundary walls all add time.
- The state of the existing wall. Sound render can usually be worked over. Cracked, hollow or damp render has to be dealt with first, and that is genuine extra work rather than an upsell.
- Detailing at openings and the roof. Window and door reveals, sills, the eaves and the verge all need proper detail. This is where a cheap job shows itself within two winters, because a poorly closed detail lets water behind the system.
- Insulation thickness. Thicker board costs more and performs better, but it also changes reveal depths and may require the roof edge to be extended.
What the SEAI grant takes off
Wall insulation falls under a grant capped at €8,000, and that cap covers external, internal or cavity work. The amount you actually receive depends on your dwelling type.
| Measure | Detached | Semi / end-terrace | Mid-terrace | Apartment |
|---|---|---|---|---|
| Attic insulation | €2,000 | €1,300 | €1,200 | €800 |
| Cavity wall | €1,800 | €1,200 | €800 | €700 |
| Wall insulation (cap) | Up to €8,000 across external, internal or cavity | |||
| Windows | €1,500–€4,000 by dwelling type | |||
| External doors | €800 per door, two maximum | |||
Homeowners on qualifying welfare payments receive fixed enhanced amounts regardless of dwelling type: €2,500 attic and €2,300 cavity wall. Figures verified against SEAI on 3 August 2026.
One point that is often missed: if you previously claimed a grant for cavity or internal wall insulation, you can now apply again for a second wall measure. That was not always the case.
Is it worth it?
Walls are responsible for roughly 40% of the heat leaving an average Irish home — more than any other surface. External insulation addresses all of it at once, and unlike internal insulation it costs you no floor area and causes almost no disruption inside the house.
It also removes thermal bridging at floor and wall junctions, which internal systems struggle with, and it keeps the existing wall warm and dry rather than cold. On a solid-wall or hollow-block house with no cavity to fill, it is frequently the only option that makes a real difference.
The counterargument is honest too: it changes the appearance of the house, it is not appropriate on brick you want to keep visible, and it is the highest upfront cost of any single measure.
Common questions
Our current rate is {{PRICE_VERIFY}} per m² for a standard certified system including supply, installation and render finish. The total depends on your wall area, which is why we measure before quoting.
Yes. Wall insulation is grant-aided up to €8,000, covering external, internal or cavity. The amount you receive depends on your dwelling type — a detached house receives more than an apartment.
A typical semi-detached house takes {{PRICE_VERIFY}} working days including scaffolding, allowing for render curing time between coats. Weather affects this more than anything else.
No. That is the main advantage over internal insulation. The system goes on the outside, so you lose no internal floor area at all.
Render needs temperatures above roughly 5°C to cure properly and must not be applied in driving rain or frost. We work through winter but schedule render around the weather rather than forcing it.
Want a figure for your own house?
A measured survey gives you the actual cost and the grant that applies. €100, refunded in full when you order.
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