Insulate first, then the windows
Insulate first, then the windows. The attic and the walls decide whether a home passes the heat loss test, and SEAI says a home without adequate attic and wall insulation can qualify once it's upgraded, with grants for that work. One application can include several grants.
The attic and wall grants that get a home ready, by home type, and why the order matters.
Free, no obligation. One registered contractor prices it, not five.
- €1,500attic grant, semi-D
- €1,300cavity wall grant, semi-D
- €3,500internal wall grant, semi-D
- €6,000external wall grant, semi-D
Why insulation comes first
SEAI calls insulation a prerequisite, not an optional extra. Without it, heat escapes through the roof and walls before it reaches the windows, so new glass in an under-insulated home doesn't give the comfort or the savings people expect, and damp or uneven heating can get worse.
The insulation grants
| Home type | Attic | Cavity wall | Internal wall | External wall |
|---|---|---|---|---|
| Detached | €2,000 | €1,800 | €4,500 | €8,000 |
| Semi-D or end of terrace | €1,500 | €1,300 | €3,500 | €6,000 |
| Mid-terrace | €1,400 | €850 | €2,000 | €3,500 |
| Apartment | €1,100 | €700 | €1,500 | €3,000 |
A home gets one wall measure, the one that suits its walls. Since 2 March 2026 a home that had a cavity or internal wall grant can add a second wall measure.
Is your home ready for the windows grant?
Four quick taps. You see where your home stands, what has to come first and every grant on the way. Your number is only asked for at the end, if you want a price.
A semi-D with the attic done and cavity walls never filled: 1 step first, the €1,300 cavity grant, then €3,000 for the windows and up to €1,600 for two doors.
How this is worked out
SEAI's windows and doors grant needs a Good or Very Good Heat Loss Indicator on the BER Advisory Report after the work, which SEAI says an HLI below 2.3 meets. Attic and wall insulation rated Good or Very Good on your report means you meet the standard. The grants are SEAI's fixed amounts for your home type, and the doors grant is shown for two doors. The check is a guide: a BER assessor and SEAI decide.
The higher rate
Homeowners on certain welfare payments, and landlords with a HAP or RAS tenant, get a higher attic and cavity wall grant:
| Home type | Attic, higher rate | Cavity wall, higher rate |
|---|---|---|
| Detached | €2,500 | €2,300 |
| Semi-D or end of terrace | €1,900 | €1,700 |
| Mid-terrace | €1,800 | €1,100 |
| Apartment | €1,400 | €900 |
First-time buyers of a second-hand home bought after 1 January 2025 that they live in also get the higher attic rate.
Where to read more
- The attic grant in detail: attic insulation grant amounts.
- Cavity walls: the cavity wall insulation grant.
- Which wall insulation your house needs: wall insulation grants.
Questions people ask
Do I have to insulate before I get the windows grant?
Insulate first, then the windows. The attic and the walls decide whether a home passes the heat loss test, and SEAI says a home without adequate attic and wall insulation can qualify once it's upgraded, with grants for that work. One application can include several grants.
Which insulation grants are there?
Attic insulation, and one wall measure: cavity, internal (dry lining) or external (the wrap). For a semi-D: €1,500, €1,300, €3,500 or €6,000.
Can the insulation and the windows go in one application?
Yes. One application can include more than one grant. Do the insulation before the windows.
Is there a higher rate?
For the attic and cavity wall grants, for homeowners on certain welfare payments and landlords with a HAP or RAS tenant.
Check your home in four taps
Where you stand, what comes first and every grant on the way. Then, if you want, one SEAI-registered contractor who covers your county rings with a price.