Wall insulation grant questions

It depends on the job and the home. For a semi-D: €1,300 for cavity wall insulation, €3,500 for internal (dry lining) and €6,000 for external. For a detached house: €1,800, €4,500 and €8,000.

Typically €300 to €600 for cavity wall, €4,100 to €7,800 for internal (dry lining) and €8,300 to €18,500 for external insulation, depending on the home. See the cost guide.

A cavity fill is usually done in a day. External insulation takes about two weeks on site for an average semi-D, weather permitting. Dry lining goes room by room, so ask the contractor how many days your rooms need.

A cavity fill means small holes drilled outside and filled after; nothing happens inside. External insulation means scaffold for a few weeks, and nothing inside either. Dry lining is the messy one: each room is cleared, and sockets, radiators and skirting come off and go back.

Ask for it in writing before you sign: the product's certificate, the warranty, and who stands over the work afterwards. The contractor fills in SEAI's paperwork for your claim.

The one that fits how your walls are built. A cavity wall that's empty gets the cavity grant. A solid or hollow block wall needs internal or external insulation, and you choose which. See which wall insulation.

Only for cavity walls: up to €2,300 for a detached house, for homeowners on certain welfare payments and landlords with a HAP or RAS tenant. Internal and external insulation have one rate.

No. SEAI says all external walls must be fully insulated; partial insulation isn't eligible. See one room or one wall.

After the work, yes: a BER assessor rates the home, and SEAI adds €50 towards that BER. It's part of your claim.

A cavity fill pays back fastest: after the grant a semi-D typically pays €285. Internal and external insulation cost more, but they're the only way to insulate a solid wall, and the grant covers about a third to a half.

One SEAI-registered insulation contractor who covers your area. They check how the walls are built, price the job in writing, do the work and deal with you directly. Nothing is booked until you say yes.

No. We pass your request to one SEAI-registered insulation contractor who covers your area. SEAI decides every grant. wallinsulationgrants.ie is not SEAI or a government body and does not award grants.

Yes, and under SEAI's whole-surface rule you must insulate both so that every external heat-loss wall of the home reaches 0.27 W/m²K or lower. However, SEAI only pays one wall insulation grant per application—the grant rate for whichever wall measure covers the larger square-metre area of external wall.

Fitting a high-performance PIR insulated plasterboard laminate or insulated timber/metal stud frame to reach the 0.27 W/m²K SEAI standard typically adds 65 mm to 95 mm in thickness to the inside of each external wall. Radiators, skirting boards, window boards and electrical sockets on those outside walls are moved forward and refitted.

Yes. Under SEAI's Better Energy Homes rules, a property cannot receive the same wall measure twice, but a home that previously had grant-aided cavity wall pumping can still apply for a second wall grant for either internal dry lining (€1,500 to €4,500) or external wall insulation (€3,000 to €8,000).

SEAI's Quality Alert and Domestic Technical Standards require a whole-surface wall solution across all external heat-loss walls of the dwelling. Leaving one elevation or room uninsulated concentrates condensation and mould on the cold uninsulated wall and fails the scheme's thermal bridging and U-value rules.

Yes. Private landlords can claim the standard SEAI cavity, internal dry-lining and external wall wrap grants on any rental property built and occupied before 2011, and since 6 October 2026 landlords letting to HAP or RAS tenants also qualify for the higher cavity wall grant rate (€1,700 on a semi-D, €2,300 detached).

You lose the grant completely. SEAI's Better Energy Homes scheme strictly prohibits retrospective payment for work started or materials installed on site before the grant offer is issued. Always wait until your online application is approved and your contractor confirms registration before work begins.