External wall insulation is the most expensive single insulation measure and the one where quotes vary most. SEAI's completion data for the first half of 2026 puts the median at €14,000 for a mid terrace and €26,500 for a detached house, against fixed grants of €3,500 and €8,000. Documented Irish jobs run about €200 to €300 per square metre of wall, and the only way to compare three quotes fairly is to work out that figure for yourself.
| House | Total cost | Grant | Paid | Source |
|---|---|---|---|---|
| Detached, median completed job | €26,500 | €8,000 | €18,500 | SEAI, Jan to Jun 2026 |
| Semi-detached or end terrace, median | €23,219 | €6,000 | €17,219 | SEAI, Jan to Jun 2026 |
| Mid terrace, median | €14,000 | €3,500 | €10,500 | SEAI, Jan to Jun 2026 |
| Apartment, median | €11,300 | €3,000 | €8,300 | SEAI, Jan to Jun 2026, five homes only |
| 44 sq m bungalow with 85 sq m of wall | €25,655 inc VAT | €8,000 | €17,655 | boards.ie 2024 quote, anonymous |
| Bungalow with 55 sq m of wall, completed 2012 | €14,000 to €15,000 | about €4,000 to €5,000 | €10,000 | boards.ie, anonymous |
| 1969 hollow block, Dublin, 150mm plus attic top up | not published | not itemised | €14,000 net | Irish Times, completed |
| 1970s four bed semi, wrap line in an itemised quote | €36,000 | part of a €20,000 package grant | not separable | askaboutmoney 2023, anonymous |
| 110 sq m dormer, wrap line in a One Stop Shop quote | about €80,000 | included in the net figure | did not proceed | boards.ie 2023, anonymous |
| Same wrap, One Stop Shop bundle against direct contractors | €31,000 ex VAT against €18,000 | not applicable | did not proceed | boards.ie 2024, anonymous |
The SEAI figures are medians, so half of all completed jobs cost more. The apartment median is based on only five completed homes for January to June 2026 and should be treated as indicative. Forum figures are anonymous and are labelled as such. Quotes and completed jobs are shown separately because a quote is what you were asked to pay.
External wall insulation is priced by wall area, not by floor area or by bedroom count, so a headline total tells you almost nothing until you divide it by your own wall area.
Take the two documented jobs where we know both numbers. A small bungalow with 44 square metres of floor area and 85 square metres of external wall was quoted €25,655.22 including VAT, which is €302 per square metre of wall. A bungalow with 55 square metres of wall came in at €14,000 to €15,000 in 2012, which is €255 to €273 per square metre, and that included removing and reinstating an existing pebble dash and granite finish.
Set those against SEAI's detached median of €26,500. A typical detached house has somewhere around 120 to 140 square metres of external wall, which puts the median at roughly €190 to €220 per square metre. So the working range across documented Irish jobs is about €200 to €300 per square metre of wall, with the small houses at the top of it.
Walk the outside of the house with a tape. Perimeter multiplied by wall height, minus the area of the windows and doors. Write the number down.
That one figure converts three wildly different totals into three comparable prices. It also tells you very quickly whether a quote has been priced off a drawing or off a visit.
If your house is a dormer or has a lot of gable, expect the wall area to be larger than you guessed and the scaffolding to be more expensive than you hoped.
Scaffolding, setting up, delivery, the render mix and the labour of detailing every window reveal are close to fixed costs. Spread them over 85 square metres of wall and they hurt. Spread them over 150 and they do not.
That is the whole reason a 44 square metre bungalow came out at €302 per square metre while bigger jobs land nearer €200. It is not that somebody was overcharged. It is that small jobs have bad unit economics, and the grant does not adjust for it.
The grant makes this worse, because it is fixed by house type rather than by wall area. A detached house gets €8,000 whether the wrap costs €18,000 or €30,000. On the €25,655 quote above the €8,000 grant covered 31 per cent. On the SEAI detached median it covers 30 per cent. Nobody is getting 50.
Scaffolding, which on a two storey house with awkward access can be several thousand euro on its own. Ask whether it is included and for how many weeks.
Removing and reinstating whatever is on the wall now. Pebble dash and granite finishes have to come off and go back. One documented job carried exactly that and it is a line that is regularly missing from a first quote.
Gutters, downpipes, soil pipes, external taps, meter boxes, satellite dishes and alarm boxes all have to come off and be refitted 150mm further out. Window sills usually have to be extended or replaced. Door thresholds have to be dealt with.
Making good. Ask specifically what the finish is: a basic scratch coat, a through colour silicone render, or something decorative. The difference between them on a whole house is thousands.
And the thing nobody prices, which is a wall that turns out to be wetter or in worse condition than expected once the old finish is off.
SEAI will only pay the external wall insulation grant for a whole surface solution. All external walls have to be fully insulated. You cannot do the gable and the back this year and the front next year and claim twice.
That single rule is why external wall insulation so often turns into a bigger project than intended, and why it is the measure most likely to be the reason a homeowner ends up on the One Stop Shop route rather than doing things measure by measure.
There is one piece of good news from 2 March 2026: homeowners who previously received a cavity or internal wall insulation grant can now apply for a second wall insulation measure. Before that, one wall grant per home was the end of it. Full detail on our external wall insulation grant page.
One homeowner had the same external wrap priced at €31,000 ex VAT inside a One Stop Shop bundle and at about €18,000 in verbal quotes from direct contractors. Project management inside that bundle alone reached €8,000.
Another was quoted about €80,000 for the external insulation line on a 110 square metre dormer bungalow, while other posters priced the entire scope of works at about €90,000 gross. He did not proceed.
Neither of those is proof that every bundle is overpriced, and both are anonymous forum accounts. What they establish is that the spread exists and that being SEAI registered does not close it. Price the wrap separately with two direct contractors even if you intend to use a One Stop Shop, purely so you know what the bundle is costing you.
If your walls are solid and external insulation is out because of a protected structure, a terrace with no side access, or a planning issue, internal dry lining is the alternative and it is dramatically cheaper. SEAI's 2026 medians put internal wall insulation at €8,600 for a detached house against €26,500 for external, with a €4,500 grant rather than €8,000.
You lose room size, all the electrics and skirtings have to come off and go back, and it does nothing for cold bridging at the joists and internal walls. It is a compromise, not an equivalent.
If your walls are cavity and in good condition, pumping the cavity is cheaper again at a median of €2,350 on a detached house with an €1,800 grant. Do that first and see how the house feels before you commit to a wrap. Compare all three on our cavity and internal wall pages.
Tell us your county and we will introduce SEAI registered wall insulation installers covering your area. No cost, no obligation.
On SEAI's completion data for January to June 2026 the median is €11,300 for an apartment, €14,000 for a mid terrace, €23,219 for a semi-detached and €26,500 for a detached house. Documented individual jobs run about €200 to €300 per square metre of wall.
About €200 to €300 per square metre of wall across the documented Irish jobs we could trace. A 44 square metre bungalow with 85 square metres of wall was quoted €25,655 including VAT, which is €302 per square metre. Larger houses land nearer €200.
€3,000 for an apartment, €3,500 for a mid terrace, €6,000 for a semi-detached or end of terrace and €8,000 for a detached house. It is a fixed amount, not a share of your quote, so on the 2026 medians it covers about 25 to 30 per cent of the job.
Not with a grant. SEAI requires a whole surface solution, meaning every external wall must be fully insulated. Partial insulation is not eligible. From 2 March 2026 you can claim a second wall insulation measure if you previously took a cavity or internal wall grant.
Usually wall area, house shape or what is on the wall now. Scaffolding and window reveals are close to fixed costs, so small houses cost more per square metre. Removing and reinstating pebble dash, moving gutters and downpipes, extending window sills and the choice of render finish all move the number.
Not on the evidence we found. One documented case had the same wrap at €31,000 ex VAT inside a bundle against €18,000 in verbal quotes from direct contractors, with €8,000 of project management inside the bundle. Price the wrap separately even if you intend to use a One Stop Shop.
Slowly. One Dublin homeowner spent €14,000 net on 150mm plus an attic top up and saves about €600 a year in oil, which is over twenty years to break even on his own figures. A bungalow owner who spent €10,000 net in 2012 reports €6,000 saved over five years, which is closer to eight years. Most satisfied homeowners talk about comfort rather than payback.
Checked against the official pages on 27 August 2026. Grant terms change, so confirm current amounts with SEAI or your installer before you commit.