External wall insulation carries the biggest SEAI grant of any single insulation measure, up to €8,000 on a detached house. It is also the most expensive job on the list and the one most likely to go wrong if your house is not right for it.
| Upgrade | Apartment | Mid-terrace | Semi-D / end | Detached |
|---|---|---|---|---|
| External wall insulation | €3,000 | €3,500 | €6,000 | €8,000 |
SEAI fixed grant amounts, current at August 2026. The grant is a fixed sum, not a percentage of your quote.
The external wall insulation grant is a fixed amount set by your dwelling type. A detached house gets €8,000 whether the job costs €18,000 or €30,000. That is the single most misunderstood thing about it. The grant does not scale with your quote, so every euro of overspend is yours.
SEAI will only pay it for a whole-surface solution. In their words, all external walls of your home must be fully insulated, and partial insulation is not eligible. You cannot do the gable and the back and leave the front for next year.
Add up everything you might do at the same time on the grant calculator, because attic insulation and wall insulation are usually done together and the attic grant is worth €1,100 to €2,000 on top.
Nobody publishes a real price, so here are documented ones. A bungalow with roughly 55 square metres of wall area came in at about €14,000 to €15,000, which left about €10,000 to pay after the grant. A four bed dormer in Galway, built in 2007, spent €15,700 on insulation and received nothing back at all.
As a rough guide, most whole-house external insulation jobs in Ireland land somewhere between €180 and €280 per square metre of wall area before the grant, and the spread inside that range is driven by scaffolding, the number of window and door reveals, whether your gutters and downpipes have to come off and go back, and whether the render finish is a basic scratch coat or something decorative.
Measure your own wall area before you ring anyone. Perimeter of the house multiplied by wall height, minus the windows and doors. That one number turns three wildly different quotes into three prices per square metre you can actually compare.
It can, and this is worth saying plainly. External wall insulation is a weatherproofing system as much as an insulation system. When it fails, it fails at the joins. Cracked render at wall junctions, water getting in behind the boards at a badly detailed sill, and cold spots left at window reveals that then attract condensation and mould in the exact corner you were trying to fix.
Almost none of that is caused by the insulation itself. It is caused by detailing. Ask any installer to walk you through, in order, how they will handle window and door reveals, the eaves, the sills, the damp proof course at the bottom, the meter boxes and the vents. If they cannot answer that from memory, they do not do this often enough.
If your walls are damp now, insulating them will not dry them out. Fix the cause first, whether that is a leaking gutter, a raised ground level bridging the damp proof course, or a cracked outer leaf. Wrapping a wet wall in insulation traps the water where you cannot see it.
It suits solid walls, hollow concrete block walls that cannot be pumped, and houses that were already going to need re-rendering. It also suits anyone who does not want to lose room space or move out, because all the work happens outside.
It suits you less well if you have a brick or stone facade worth keeping, if your walls sit tight to a footpath or a boundary so the extra 100mm to 150mm has nowhere to go, or if your house is a protected structure or sits in an architectural conservation area.
If the house has a cavity that can be filled, do the maths before jumping to external. Cavity wall insulation costs a fraction as much and can be done in a day. It will not get you as far, but it gets you a long way for very little.
External insulation changes the outside of your house, which is why it sits in a grey area. Work that alters the external appearance of the building, or leaves it out of character with neighbouring houses, can require planning permission. Protected structures and architectural conservation areas need checking every time.
The Irish Times reported the case of a Dublin homeowner who fitted wraparound external insulation in 2018, with an SEAI grant, and was later told by South Dublin County Council that the work did not meet planning requirements and had to come down. An SEAI grant is not planning approval and it never was.
The fix costs very little. Write to your local authority for a section 5 declaration under the Planning and Development Act 2000 confirming that what you propose is exempted development. Do it before you sign with a contractor, not after.
Your home must have been built and occupied before 31 December 2010 to qualify for any SEAI insulation grant, and it must have an MPRN. There is no discretion on this one and no appeal.
The other refusals are all avoidable. You must have grant approval in place before any work starts, so a contractor who offers to start on Monday and sort the paperwork after has just cost you the grant. Your contractor must be on the SEAI registered list for wall insulation specifically, not just registered for something else. Every external wall has to be done. And if you have already claimed an external wall insulation grant at that MPRN, you cannot claim a second wall measure of any kind.
You can go the other direction though. If you previously got a grant for cavity or internal wall insulation, you can now apply for external wall insulation as a second wall measure. That rule came in on 2 March 2026 and it is new, so older articles and forum threads saying otherwise are out of date.
The worry that the price goes up once you say the word grant is not paranoia, and the way around it is straightforward. Get the full price in writing first, per square metre, before you mention SEAI at all. Then ask what the grant changes. A quote that moves by roughly the grant amount tells you everything.
Ask three specific questions. What insulation system are you using and what is its NSAI Agrément number. How thick, and what U-value does the finished wall reach. Who carries out the BER afterwards and is that in your price or extra.
Get three quotes from SEAI registered contractors and expect them to differ. A cheap external insulation job is not a bargain, it is a render repair bill in five years.
You apply, you get a grant offer, and you have 30 days to accept it. From the date of that offer you have eight months to finish the works. Miss the window and you reapply at whatever the rates are then.
After the work is done you need a post-works BER assessment before SEAI will pay. There is a €50 BER grant towards the cost of it, which does not cover it. See the BER guide for what an assessment involves and how to avoid being scored down on insulation the assessor cannot see.
The grant is paid to you, not the contractor, unless you nominate the contractor's account so you only pay the price net of the grant. Useful to know: if your SEAI grants total more than €10,000 in a year, and external insulation on a detached house plus an attic gets you close, you will need a tax clearance certificate.
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€3,000 for an apartment, €3,500 mid-terrace, €6,000 semi-detached or end of terrace, and €8,000 detached. It is a fixed amount, not a share of your quote.
Most whole-house jobs work out between roughly €180 and €280 per square metre of wall area before the grant. A documented bungalow job with about 55 square metres of wall came to €14,000 to €15,000, leaving about €10,000 after the grant. Measure your wall area and compare quotes per square metre.
Often not, but it is not automatic. Work that changes the external appearance or leaves the house out of character with its neighbours can need permission, and protected structures and architectural conservation areas need checking. Apply to your local authority for a section 5 declaration before you commit. An SEAI grant does not stand in for planning.
Yes. Since 2 March 2026 you can claim external wall insulation as a second wall measure if you previously got a cavity or internal wall insulation grant. If you already claimed external wall insulation at that MPRN, you cannot claim another wall measure.
Not if the detailing is right and the wall was dry to start with. Failures happen at reveals, sills, eaves and the base of the wall, not in the middle of the panel. Fix any existing damp cause first, and ask your installer to talk you through the detailing before you sign.
Yes. SEAI requires a whole-surface solution, so all external walls must be fully insulated. Doing one or two walls is not eligible.
Not an insulation grant. Insulation grants require the home to have been built and occupied before 31 December 2010. Some other measures use different dates and rules, so it is worth checking the individual measure on the <a href="/grants/">grants overview</a> before you rule yourself out entirely.
Checked against the official pages on 27 August 2026. Grant terms change, so confirm current amounts with SEAI or your installer before you commit.