What home energy upgrades cost in Ireland
A single upgrade to a detached house runs from €2,250for cavity wall insulation to €24,980 for external wall insulation. Doing the whole house through a One Stop Shop has a median cost of works of€69,795, of which the homeowner pays a median of€45,067 once grants are deducted.
Every figure here is SEAI's own, from what contractors actually charged on 47,067 completed upgrades. Where SEAI publishes no cost, we say so instead of guessing.
Cost by upgrade
| Upgrade | Median cost | SEAI grant | You pay |
|---|---|---|---|
| Cavity wall insulation | €2,250 | −€1,800 | €450 |
| Attic insulation | €2,519 | −€2,000 | €519 |
| Heating controls | €3,500 | −€700 | €2,800 |
| Internal wall insulation | €9,000 | −€4,500 | €4,500 |
| Solar panels | €10,730 | −€1,800 | €8,930 |
| Heat pump | €16,500 | −€10,500 | €6,000 |
| External wall insulation | €24,980 | −€8,000 | €16,980 |
| BER assessmentAn assessment, not an upgrade | €280 | No grant | €280 |
Figures are for a detached house, which is the dearest of the four house types for almost every measure. Each page breaks the cost down for semi-detached, mid terrace and apartment too.
Where these figures come from
SEAI,Better Energy Homes and Solar PV: individual energy upgrades costs and grants. Based on 47,067 energy upgrades completed through the Better Energy Homes and Solar PV Scheme, January to December 2025.
Whole-house figures: SEAI,National Home Energy Upgrade Scheme: one stop shop energy upgrades median costs and grants. Based on 1,406 private homes completed through One Stop Shops, January to December 2025.
Both documents checked figure by figure on 2026-08-13.
Doing the whole house at once
A One Stop Shop manages the full upgrade and deducts the grants from the bill up front, so the homeowner never handles the grant paperwork. These are different projects from the single measures above, and the totals are not the individual medians added together.
| House type | Median cost of works | Median grant | You pay | BER |
|---|---|---|---|---|
| Detached | €69,795 | €24,500 | €45,067 | D2 to A2 |
| Semi-detached or end of terrace | €60,805 | €21,700 | €38,932 | D2 to A2 |
| Mid terrace | €55,250 | €18,813 | €37,266 | E1 to A2 |
| Apartment | €30,345 | €11,300 | €20,235 | D1 to A3 |
Each column is a separate median across the same 1,406 homes, so the three do not subtract exactly. The median grant did not necessarily go to the same house as the median cost of works.
What the 1,406 projects actually cost
74% of whole-house projects cost more than €50,000 before grants. If you have been quoted well under that for a full upgrade, check carefully what is included.
Where there is no official cost
SEAI does not publish a median for everything it grant-aids. Rather than estimate one, here is what is missing and why.
Windows and doors
No SEAI median: the grant only opened in 2026. The page carries the grant amounts, which are confirmed, and one named supplier's published price list, labelled as one company's prices rather than a national average.
What is actually published →Ventilation
Ventilation is normally carried out as part of a larger upgrade rather than on its own, and SEAI does not publish a separate median for it. It appears in the whole-house figures below.
Solar water heating
SEAI publishes a median for solar PV but not for solar water heating, which is a separate and much less common measure.
What the grant is worth →See what your own home qualifies for
Answer a few questions about the house and get the grant total across every upgrade it is eligible for. We email you the contractor contacts to approach yourself, and we do not share your details with them.
Common questions
How much does a home energy upgrade cost in Ireland?
It depends entirely on whether you do one upgrade or the whole house. Single upgrades range from €2,250 for cavity wall insulation to €24,980 for external wall insulation on a detached house. A whole-house upgrade through a One Stop Shop has a median cost of works of €69,795 for a detached house, of which the homeowner pays a median of €45,067 after grants.
What is the cheapest home energy upgrade?
Cavity wall insulation is the cheapest upgrade SEAI publishes a median for, at €2,250 for a detached house and €950 for an apartment. Attic insulation is next, at €2,519 for a detached house. Both are usually the first upgrades worth doing, and both carry a grant that covers most of the bill.
Do these figures include the SEAI grant?
No. The median cost is the full cost of the work before any grant. Each page also shows what is left after the grant for that measure, and the grant is paid to you after the work is finished, so you pay the contractor in full first.
Where do these costs come from?
SEAI's own published figures, from 47,067 energy upgrades completed through the Better Energy Homes and Solar PV Scheme, January to December 2025, and from 1,406 private homes completed through One Stop Shops for the whole-house figures. Median costs are calculated from the costs submitted to SEAI by registered contractors and One Stop Shops at the time of grant payment. The median is the mid-point of all upgrade costs: half of upgrades cost less, half cost more.
Why is there no cost for windows and doors?
SEAI has not published a median for windows and doors, because the grant only opened in 2026 and no full year of cost data exists yet. Rather than estimate one, the windows and doors page sets out what the grant is worth and what Irish suppliers publish as their own list prices, labelled as exactly that.