What Homeowners Paid (and What SEAI Covered) – SEAI 2025 Median Costs & Grants
If you’re thinking about improving your home’s comfort and energy efficiency, one of the first questions is usually: what will it cost, and how much will SEAI cover?
SEAI has published two very useful snapshots covering January to December 2025:
- Individual energy upgrades under the Better Energy Homes and Solar PV scheme (step-by-step upgrades)
- One Stop Shop upgrades under the National Home Energy Upgrade Scheme (a managed, multi-measure “complete upgrade”)
Both datasets use median figures. Median is the midpoint: half of the upgrades cost less, and half cost more.
What this data is (and what it isn’t)
These figures are designed to help homeowners budget realistically. They’re not quotes, and your own costs will depend on the home, the measures chosen, access, and the condition of the existing building fabric and heating system.
Also, these are 2025 figures. SEAI grant values can change over time, so always check current SEAI grant pages (or confirm with your provider) before making decisions. The great news is that the SEAI has enhanced grants and created new ones for 2026.
Route 1: Individual upgrades (Better Energy Homes + Solar PV)
This route suits homeowners who want flexibility to upgrade step-by-step to match their budget and timing.
SEAI states this dataset is based on a sample of 47,067 energy upgrades completed from January to December 2025.
Heat pump
| Home type | Median cost | Fixed grant |
| Detached | €16,500 | €6,500 |
| Semi-D / End terrace | €16,832 | €6,500 |
| Mid-terrace | €15,000 | €6,500 |
| Apartment | €10,067 | €4,500 |
Attic insulation
| Home type | Median cost | Fixed grant |
| Detached | €2,519 | €1,500 |
| Semi-D / End terrace | €2,000 | €1,300 |
| Mid-terrace | €2,000 | €1,200 |
| Apartment | €1,894 | €800 |
Cavity wall insulation
| Home type | Median cost | Fixed grant |
| Detached | €2,250 | €1,700 |
| Semi-D / End terrace | €1,550 | €1,200 |
| Mid-terrace | €1,100 | €800 |
| Apartment | €950 | €700 |
Internal wall insulation
| Home type | Median cost | Fixed grant |
| Detached | €9,000 | €4,500 |
| Semi-D / End terrace | €10,420 | €3,500 |
| Mid-terrace | €6,303 | €2,000 |
| Apartment | €3,640 | €1,500 |
External wall insulation
| Home type | Median cost | Fixed grant |
| Detached | €24,980 | €8,000 |
| Semi-D / End terrace | €23,247 | €6,000 |
| Mid-terrace | €14,244 | €3,500 |
| Apartment | €17,450 | €3,000 |
Note: SEAI states apartment data for external wall insulation is based on six applications received for 2025.
Solar PV
SEAI’s Solar PV grant is shown as a maximum grant of €1,800.
SEAI notes the grant is calculated as €700 per kWp up to 2kWp, plus €200 for every additional kWp up to 4kWp, capped at €1,800.
BER (Building Energy Rating)
| Home type | Median cost | Fixed grant |
| Detached | €280 | €50 |
| Semi-D / End terrace | €276 | €50 |
| Mid-terrace | €276 | €50 |
| Apartment | €250 | €50 |
Heating controls
| Home type | Median cost | Fixed grant |
| Detached | €3,500 | €700 |
| Semi-D / End terrace | €3,500 | €700 |
| Mid-terrace | €3,054 | €700 |
| Apartment | €4,646 | €700 |
Route 2: One Stop Shop “complete upgrade” (National Home Energy Upgrade Scheme)
This route suits homeowners who want to upgrade their home in one managed project, with an SEAI-registered One Stop Shop coordinating the works.
SEAI states this dataset is based on median costs for 1,406 private homes completed through One Stop Shops (January to December 2025).
Median works cost, median grant, and median cost to homeowner
| Home type | Median works cost | Median grant | Median cost to homeowner |
| Apartment | €30,345 | €11,300 | €20,235 |
| Mid-terrace | €55,250 | €18,813 | €37,266 |
| Semi-D / End terrace | €60,805 | €21,700 | €38,932 |
| Detached | €69,795 | €24,500 | €45,067 |
Typical upgrades included (examples)
SEAI lists typical measures included in these One Stop Shop upgrades as:
- Heat pump
- Windows and doors
- Wall insulation
- Attic insulation (for most house types)
- Ventilation
- Solar panels (often)
Key figures from the One Stop Shop dataset
SEAI also shares a helpful cost distribution for One Stop Shop upgrades:
- 5% received energy upgrades at a cost of < €30,000
- 21% received energy upgrades at a cost of €30,000-€50,000
- 40% received energy upgrades at a cost of €50,000-€75,000
- 34% received energy upgrades at a cost of > €75,000
Which route is right for you?
There’s no one-size-fits-all answer – it depends on your home, budget, and how quickly you want to see results. Here’s a simple way to think about it:
- Choose individual upgrades if you want to spread the work over time, start with a quick comfort win (like attic insulation), or you’re not ready to commit to a full home upgrade in one go.
- Choose One Stop Shop if you want a fully managed project, you’d prefer one coordinated plan, and you want to upgrade multiple measures together (for example, insulation + heat pump + ventilation).
- If you’re unsure, start with a conversation and a plan. The “best” route is the one that fits your home and helps you avoid doing work twice.
How to use this when planning your upgrade
If you’re trying to decide where to start, a practical approach is:
- Start with heat-loss measures (attic and wall insulation) where they make sense for your home.
- Then look at heating (heat pump) once the home is “heat pump ready”.
- Add solar PV if you want to generate electricity and support lower running costs.
- Don’t skip ventilation considerations if you’re making the home more airtight.
Want help choosing the best route?
If you’d like help understanding what these numbers mean for your home – and whether a step-by-step approach or a One Stop Shop “complete upgrade” makes more sense – get in touch. We’ll talk you through the options and help you plan the right sequence. Fill out our form at www.leetherm.ie/oss.
