SEAI median costs · January to June 2026
Wall insulation cost after the grant
On a semi-D, SEAI's median cost is €1,585 for cavity, €9,843 for internal and €23,219 for external insulation. After the grant that leaves about €285, €6,343 and €17,219 (SEAI median costs).
SEAI's own medians from 23,412 grant-funded upgrades, the grant against each, and what pushes a price up.
Figures checked against SEAI and Citizens Information on 2 November 2026. wallinsulationgrants.ie is not SEAI or a government body and does not award grants.
- €8,000SEAI's fixed external wall grant for a detached house, the biggest of the three
- €4,500for internal wall insulation (dry lining) on a detached house (SEAI)
- €2,300the higher cavity grant for a detached house, for certain welfare recipients and HAP or RAS landlords (Citizens Information)
- 24%of homes on the BER register with a known wall type have solid or hollow block walls: no cavity to fill (SEAI BER register)
FreeNo obligationOne contractor rings you, not fiveSEAI approves the grant before any work
Grant check
Your wall grant and what's left to pay
Three taps: the wall job, your home, and which rate fits you. The answer is SEAI's fixed grant and its own median cost for the job.
Your SEAI wall insulation grant
€3,500
- SEAI median cost, Jan to Jun 2026
- €9,843
- Left to pay at the median
- €6,343
SEAI's fixed internal (dry lining) grant for a semi-d or end of terrace at the standard rate is €3,500 (Citizens Information and SEAI, 2 November 2026). SEAI's median cost for that job on a semi-d or end of terrace, January to June 2026, was €9,843. €9,843 less €3,500 leaves about €6,343. Our sum; your quote can be higher or lower.
Send this for a real priceHow this is worked out
The grant is SEAI's fixed amount for that wall job and home type, as SEAI's wall insulation page and Citizens Information (Citizens Information, updated 22 October 2026) list it. The higher rate applies to cavity walls only. The median cost is SEAI's own figure from grant-funded jobs completed between January and June 2026 (SEAI median costs); the PDF doesn't say whether VAT is in. Left to pay is the median less the grant, our sum. The home must have been built and lived in before 2011, every external wall must be done, the contractor must be on SEAI's register, and SEAI must approve the grant before work starts. It's an estimate, never a quote.
Every job
Median cost, grant and what's left
| Job | Home type | Median cost | Grant | Left to pay | Grant covers |
|---|---|---|---|---|---|
| Cavity wall | Detached house | €2,350 | €1,800 | €550 | 77% |
| Semi-D or end of terrace | €1,585 | €1,300 | €285 | 82% | |
| Mid-terrace | €1,250 | €850 | €400 | 68% | |
| Apartment | €1,036 | €700 | €336 | 68% | |
| Internal (dry lining) | Detached house | €8,600 | €4,500 | €4,100 | 52% |
| Semi-D or end of terrace | €9,843 | €3,500 | €6,343 | 36% | |
| Mid-terrace | €9,804 | €2,000 | €7,804 | 20% | |
| Apartment | €5,736 | €1,500 | €4,236 | 26% | |
| External (the wrap) | Detached house | €26,500 | €8,000 | €18,500 | 30% |
| Semi-D or end of terrace | €23,219 | €6,000 | €17,219 | 26% | |
| Mid-terrace | €14,000 | €3,500 | €10,500 | 25% | |
| Apartment | €11,300 | €3,000 | €8,300 | 27% |
SEAI's median costs and fixed grants, January to June 2026 (SEAI median costs). Left to pay and the share the grant covers are our sums.
Cavity
Cavity wall insulation cost
| Home type | SEAI median cost | Grant | Left to pay |
|---|---|---|---|
| Detached house | €2,350 | €1,800 | €550 |
| Semi-D or end of terrace | €1,585 | €1,300 | €285 |
| Mid-terrace | €1,250 | €850 | €400 |
| Apartment | €1,036 | €700 | €336 |
Cavity wall: SEAI's median cost of grant-funded jobs, January to June 2026 (SEAI median costs). Left to pay is the median less the standard grant: our sum.
The lowest-cost job of the three, and the grant covers most of it. At the higher cavity rate a semi-D's €1,700 grant leaves about €0 (Citizens Information, our sum).
Internal
Internal wall insulation cost
| Home type | SEAI median cost | Grant | Left to pay |
|---|---|---|---|
| Detached house | €8,600 | €4,500 | €4,100 |
| Semi-D or end of terrace | €9,843 | €3,500 | €6,343 |
| Mid-terrace | €9,804 | €2,000 | €7,804 |
| Apartment | €5,736 | €1,500 | €4,236 |
Internal (dry lining): SEAI's median cost of grant-funded jobs, January to June 2026 (SEAI median costs). Left to pay is the median less the standard grant: our sum.
In SEAI's sample the median semi-D (€9,843) and mid-terrace (€9,804) cost more than the median detached house (€8,600). SEAI doesn't explain it. The grant still falls with the size of the home, so a mid-terrace is left with the biggest bill of the three house types. Internal wall insulation has what the job involves.
External
External wall insulation cost
| Home type | SEAI median cost | Grant | Left to pay |
|---|---|---|---|
| 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 | €8,300 |
External (the wrap): SEAI's median cost of grant-funded jobs, January to June 2026 (SEAI median costs). Left to pay is the median less the standard grant: our sum.
The biggest job and the biggest grant. SEAI notes its apartment figure comes from five homes. housewrap.ie has the external job in detail.
What moves the price
Why your quote won't match the median
- Wall area. The median main-wall area on BER certificates is about 91 m² for a semi-D and 128 m² for a detached house (SEAI BER register, our sums). Bigger walls, more material.
- Kitchens and fittings. With internal insulation, kitchens, cabinets and appliances on outside walls have to come out and go back (SEAI wall insulation guide).
- Window and door reveals. SEAI's guide says they must be insulated too (SEAI wall insulation guide).
- Meters and services. External insulation can need an ESB Networks service alteration, which can carry fees and delays (SEAI); SEAI's standard also covers the gas meter and telecoms (SEAI technical standard).
- VAT. SEAI's PDF doesn't say whether its medians include VAT. Ask for the written price with VAT shown.
Your grant
Your wall grant and a price, in 4 taps
Tap your home, which wall job you think it needs, when it was built and which rate fits you. Then leave your number and one SEAI-registered insulation contractor who covers your area rings you to look at the walls and price it in writing.
FAQ
Questions people ask
How much does it cost to insulate walls in Ireland?
SEAI's median for a semi-D, January to June 2026: €1,585 cavity, €9,843 internal, €23,219 external (SEAI median costs).
How much is internal wall insulation after the grant?
About €6,343 for a semi-D and €4,100 for a detached house at SEAI's medians (SEAI median costs, our sums).
Is external or internal insulation cheaper?
Internal, at SEAI's medians: €9,843 against €23,219 for a semi-D. After the grants, €6,343 against €17,219 (SEAI median costs).
Keep reading
Related guides
- Wall insulation grant amounts 2026All three wall grants, the higher cavity rate and what changed in 2026.
- Internal wall insulation (dry lining)Dry lining: the grant, the cost, the room you lose and the rules.
- Internal vs external insulationSame solid wall, two jobs: grant, cost, planning and disruption.
- Which wall insulation does my house need?Cavity, solid, hollow block or timber frame: which grant fits.
- How to applySeven steps, the deadlines, and the rule that loses people the grant.
- All home insulation grantsAttic and all three wall grants in one table.
Where these numbers come from (6 public sources, checked 2 November 2026)
- SEAI, individual energy upgrades: median costs and fixed grants, January to June 2026, 23,412 upgrades (PDF)
- Citizens Information, Better Energy Homes Scheme (page updated 22 October 2026)
- SEAI BER Research Tool, full public file (downloaded 29 October 2026, our sums)
- SEAI, Homeowner's Guide to Wall Insulation (PDF)
- SEAI, wall insulation grant page
- SEAI, Domestic Technical Standards and Specifications v4.0, July 2026 (PDF)