Can I get the windows grant before insulating?

No. SEAI pays the windows and doors grants only when the attic and walls are insulated, either before the windows or at the same time.

SEAI’s rule, in its own words

Windows are where many people start. SEAI’s rule is that insulation comes first, or at the same time.

If the attic and walls are not insulated enough, the windows and doors grants are not paid.
“If you don’t have sufficient insulation, you must install this before SEAI can pay grants for windows and doors.” SEAI: Upgrading windows and doors leaflet, read 25 Sept 2026
Doing the insulation in the same go as the windows is fine.
“You are planning to upgrade your insulation before or at the same time you are installing your new windows and doors.” SEAI: Upgrading windows and doors leaflet, read 25 Sept 2026
After the works, the house has to reach a heat loss indicator of 2.3, or have its attic and walls rated good.
“The property must meet a Heat Loss Indicator (HLI) value of 2.3” SEAI: Windows and doors grant, read 13 Jul 2026
The new windows must be 1.4 or better.
“You must be replacing existing single or double glaze windows with high-performing windows (1.4 or better)” SEAI: Windows and doors grant, read 13 Jul 2026

On a semi-detached house the windows grant is €3,000 and two doors are €1,600. Done in the wrong order, that is money not paid.

Each quote links to the SEAI page it is from, read on 26 September 2026. Whether a grant is paid is SEAI’s decision on your application.