Before booking insulation work, get a BER assessment. The Advisory Report tells you exactly where your home is losing heat and which measures will make the biggest difference. It’s the roadmap for your upgrade. Book a BER with Homerating.ie →
Why Insulate First?
A typical uninsulated Irish home loses 25–30% of its heat through the roof and 30–35% through the walls. Fixing those leaks is the fastest, cheapest way to make your home noticeably warmer, and it’s where SEAI wants you to start.
A well-insulated home needs a smaller heat pump, qualifies for the new windows & doors grant, and gets more value from solar panels. Everything works better when the heat isn’t escaping.
Insulation Grant Amounts (2026)
SEAI grants were increased in February 2026, with additional support for first-time buyers and those on qualifying social welfare payments.
Attic Insulation
The most cost-effective single upgrade. The SEAI grant now covers approximately 80% of the average cost for attic insulation in most homes.
| Home Type | Standard Grant | First-Time Buyer | Welfare Payment |
|---|---|---|---|
| Detached house | €2,000 | €2,500 | €2,500 |
| Semi-detached / End-terrace | €1,300 | €2,500 | €2,500 |
| Mid-terrace | €1,200 | €2,500 | €2,500 |
| Apartment | €800 | €2,500 | €2,500 |
First-time buyers of existing homes receive a flat €2,500 for attic insulation regardless of home type, that’s €500 more than the standard detached house rate. This often covers the entire cost of the work.
Cavity Wall Insulation
Quick, low-disruption, and highly effective for homes built between the 1930s and 1990s with unfilled cavity walls. Can usually be completed in a single day.
| Home Type | Standard Grant | Welfare Payment |
|---|---|---|
| Detached house | €1,800 | €2,300 |
| Semi-detached / End-terrace | €1,200 | €2,300 |
| Mid-terrace | €800 | €2,300 |
| Apartment | €700 | €2,300 |
External Wall Insulation (EWI)
The premium option for solid-wall homes. Wraps your home in an insulating layer from outside. Most expensive but most effective, with the highest grants. See our full EWI guide →
| Home Type | SEAI Grant | Typical Total Cost | Your Cost After Grant |
|---|---|---|---|
| Detached house | €8,000 | €15,000–€25,000 | €7,000–€17,000 |
| Semi-d / End-terrace | €6,000 | €10,000–€18,000 | €4,000–€12,000 |
| Mid-terrace / Apartment | €3,000 | €6,000–€12,000 | €3,000–€9,000 |
Internal Wall Insulation (Dry Lining)
Insulating from inside when external insulation isn’t practical. Reduces room size by 5–10cm per wall but avoids altering the home’s external appearance.
| Home Type | SEAI Grant |
|---|---|
| Detached house | €4,500 |
| Semi-d / End-terrace | €3,500 |
| Mid-terrace | €2,000 |
| Apartment | €1,500 |
Homes that previously received a cavity wall insulation grant can now apply for a second wall insulation measure (external or internal) to improve performance further. This is ideal for homes where cavity-only wasn’t enough.
What Does Insulation Cost? (3-Bed Semi)
| Insulation Type | Typical Cost | SEAI Grant | Your Cost | Payback |
|---|---|---|---|---|
| Attic (300mm mineral wool) | €1,500–€2,200 | €1,300 | €200–€900 | <1 year |
| Cavity wall (pumped bead) | €1,800–€2,500 | €1,200 | €600–€1,300 | 1–2 years |
| External wall (EPS/mineral) | €12,000–€18,000 | €6,000 | €6,000–€12,000 | 6–10 years |
| Internal dry lining | €8,000–€14,000 | €4,500 | €3,500–€9,500 | 5–8 years |
Attic insulation is the standout value, the grant covers 60–80% of the cost, and payback through energy savings is under a year. If your home has unfilled cavity walls, that’s the second-best bang for your buck.
Reduce costs further
- Home Energy Upgrade Loan. rates from 2.99% through AIB, PTSB, Bank of Ireland, Avant Money, and credit unions
- Landlord tax relief. deduct up to €10,000 per property (net of grants) from rental income, available to 2028
- One Stop Shop route. higher combined grants when doing multiple measures to achieve BER B2
- Energy supplier credits. obligated energy companies (Bord Gáis, Electric Ireland, Energia, etc.) offer additional credits of €500–€2,000 for insulation works
What Order Should I Upgrade?
This order matters because each step unlocks the next. Attic and wall insulation bring your HLI down, which qualifies you for the windows & doors grant (HLI ≤ 2.3) and ultimately the heat pump grant (HLI ≤ 2.0). Read our detailed sequencing guide →
Common Insulation Mistakes to Avoid
- Skipping ventilation. Insulation makes your home more airtight. Without adequate ventilation, moisture builds up and causes condensation, mould, and poor air quality. Always discuss ventilation with your contractor.
- Doing external insulation before checking cavity walls. If you have unfilled cavity walls, fill them first, it’s 80% cheaper than EWI and may be all you need.
- Not getting a BER first. Without a BER Advisory Report, you’re guessing which measures will have the biggest impact. A €150–€300 assessment saves thousands in misdirected spending.
- Using unregistered contractors. Only SEAI-registered contractors qualify for grant-aided work. Unregistered work won’t be covered and may not meet quality standards.
- Forgetting about pipes and tanks. When insulating the attic, ensure the water tank and any pipes above the insulation are lagged. Attic insulation keeps heat in the house, which means the attic itself gets colder.
Frequently Asked Questions
In most cases, yes. The new standalone windows & doors grant requires a Heat Loss Indicator (HLI) of 2.3 or below, which typically means your attic and walls must already be insulated. Get a BER assessment to check where you stand. See our full windows & doors guide →
Yes. Through the Individual Grants (Better Energy Homes) pathway, you can apply for each measure separately at your own pace. You don’t need to do everything at once.
Attic insulation alone can reduce heat loss through the roof by up to 40%, saving €200–€400 per year. Adding cavity wall insulation saves another €200–€400. External wall insulation on a solid-wall home can save €400–€800 per year. Total savings depend on your current heating system and insulation levels.
If your existing attic insulation is less than 300mm deep, it can be topped up. The SEAI grant covers this. For wall insulation, the new second wall insulation grant (from March 2026) allows you to add external or internal insulation even if you previously had cavity fill.
Attic, cavity, and internal insulation require no planning permission. External wall insulation is generally exempt for most houses, but if your home is a protected structure or in a conservation area, check with your local authority first.