Cavity wall insulation grant for a detached house
SEAI pays €1,800 for cavity wall insulation on a detached house (€2,300 on qualifying welfare payments). SEAI’s median cost for this work on this type of home is €2,350, which leaves about €550 to pay.
The figures
| Self-managed | One Stop Shop | |
|---|---|---|
| Cavity wall insulation | €1,800 | €1,800 |
| Typical cost (SEAI median) | €2,350 | its own price |
| Left to pay | €550 | plus its fees |
How many homes like this need it
Published BERs for detached houses, by when they were built: the share that record cavity walls that have not been filled.
| Built | BERs | Share |
|---|---|---|
| Before 1940 | 14,611 | 12% |
| 1940–1969 | 9,548 | 29% |
| 1970–1989 | 16,188 | 28% |
| 1990–2004 | 20,434 | 1% |
| 2005–2010 | 11,201 | 0% |
SEAI’s rules for this grant
Every external wall has to be insulated.
“To receive the grant, all external walls of your home must be fully insulated.” SEAI: Wall insulation grant, read 8 Jun 2026
Cavity and internal insulation need no planning permission.
“Planning permission is not required for internal or cavity insulation.” SEAI: Wall insulation grant, read 8 Jun 2026
Insulating the walls brings in the building regulations, which need the attic and heating up to standard.
“Have a heating system and attic insulation compliant with the Building Regulation standard” SEAI: Wall insulation grant, read 8 Jun 2026
After a cavity wall grant, internal or external insulation can follow.
“If you previously received a grant for cavity wall insulation, you can apply for an internal wall insulation grant or an external wall insulation grant.” SEAI: Wall insulation grant, read 8 Jun 2026
How to apply
1Get the grant offer first
Apply online to SEAI and wait for the offer before any work starts or materials are bought.
2Choose a registered contractor
The contractor has to be registered with SEAI for this work.
3Accept within 30 days
You have 30 days to accept the offer.
4Finish within eight months
You have eight months from the offer to finish and claim.
5Get a BER after the works
Every claim needs a BER after the works, by a registered BER assessor.
6Claim, and wait for payment
SEAI says to allow 4 to 6 weeks to process the payment.
Where it fits in the order
Grants depend on doing things in the right order. Worked plans for detached houses, by age:
Get the plan for your homeRegistered contractors, by county
2,106 listings on SEAI’s register for this work
Companies on SEAI’s register for cavity wall insulation that serve each county. Registration is a fact about paperwork; SEAI does not endorse their work. See them by county
- Carlow91
- Cavan51
- Clare85
- Cork86
- Donegal48
- Dublin79
- Galway74
- Kerry83
- Kildare92
- Kilkenny91
- Laois91
- Leitrim74
- Limerick87
- Longford87
- Louth89
- Mayo75
- Meath89
- Monaghan50
- Offaly91
- Roscommon74
- Sligo74
- Tipperary88
- Waterford87
- Westmeath88
- Wexford91
- Wicklow91