The heat pump is the most expensive single thing in most retrofits and the one with the biggest grant behind it since February 2026. SEAI's own completion data for the first half of 2026 puts the median installed cost at €16,000 to €17,000 for a house, against a fixed grant of €12,500. That leaves €3,500 to €4,500 to pay. The catch is not the heat pump. It is everything your house needs before one will work in it.
| House | Total cost | Grant | Paid | Source |
|---|---|---|---|---|
| Detached, median installed cost | €17,000 | €12,500 | €4,500 | SEAI, Jan to Jun 2026 |
| Semi-detached or end terrace, median | €16,741 | €12,500 | €4,241 | SEAI, Jan to Jun 2026 |
| Mid terrace, median | €16,000 | €12,500 | €3,500 | SEAI, Jan to Jun 2026 |
| Apartment, median | €9,025 | €9,500 max | nil at the median | SEAI, Jan to Jun 2026 |
| 1970s four bed semi, heat pump line only in an itemised quote | €18,000 | not separable | not separable | askaboutmoney 2023, anonymous |
| 165 sq m split level bungalow, Roscrea, heat pump package | €17,900 ex VAT | about €6,000 | about €12,000 | Tipperary Energy Agency via Selfbuild, 2018 |
| 210 sq m detached self build, Co Tipperary, package | €26,500 inc VAT | about €9,275 | about €17,225 | Tipperary Energy Agency via Selfbuild, 2018 |
| 175 sq m timber frame, Co Dublin, package | €20,000 inc VAT | about €7,000 | about €13,000 | Tipperary Energy Agency via Selfbuild, 2018 |
| 200 sq m stone farmhouse, Co Cork, package | €18,205 inc VAT | about €6,370 | about €11,835 | Tipperary Energy Agency via Selfbuild, 2018 |
The four Tipperary figures are heat pump led packages, not the heat pump on its own. Each included the fabric and ventilation work needed to make the heat pump viable, such as triple glazing, airtightness and demand controlled ventilation. They date from 2017 and 2018 and the 35 per cent grant shown is the rate of the day, not the 2026 rate. The SEAI medians are the installed heat pump cost submitted by registered contractors at grant payment.
Two numbers get confused constantly. The installed cost of an air to water heat pump in a house that is already ready for one is €16,000 to €17,000 at SEAI's 2026 medians. One itemised One Stop Shop quote from 2023 priced a Mitsubishi unit at €18,000 as a standalone line, which sits just above that.
The cost of getting a typical older Irish house ready for one is a different and much larger number. To qualify for the grant your home has to have a heat loss indicator of 2.3 W per K per square metre or better. Most houses built before the mid 2000s do not, which means insulation, airtightness and often windows have to come first. That is why heat pump projects turn into whole house projects.
The four Tipperary Energy Agency cases in the table above are the clearest illustration we have. Each is a heat pump plus the fabric work needed to make it viable, and they run €17,900 to €26,500 including VAT on houses of 165 to 210 square metres. That is the honest number for a heat pump on an older house: not the €17,000 for the plant, but the package around it.
From 3 February 2026 the heat pump system grant became a fixed €12,500 for a house. It breaks down as €6,500 for the heat pump itself, €2,000 for upgrading radiators and pipework, and a €4,000 renewable heating bonus for replacing a fossil fuel or solid fuel system. Before that date the grant was €6,500 and there was no bonus.
For apartments the maximum is €9,500, and an air to air system attracts €3,500 on the individual route, with €7,500 available for air to air in apartments.
This is the single biggest reason to distrust older price threads. A 2023 forum post showing a €18,000 heat pump with a €6,500 grant is describing a world that no longer exists. Run your own scope through the grant calculator against the current amounts, and read the detail on our heat pump grant page.
A heat pump runs at a much lower flow temperature than an oil or gas boiler. Radiators sized for 70 degrees will not heat a room at 45 degrees, so they have to be resized room by room. One documented Kildare installation had every radiator resized individually and all pipework insulated as part of the job.
Micro-bore pipework, common in houses built from the 1970s to the 1990s, often has to be replaced outright. That is the €2,000 central heating line inside the €12,500 grant, and on a big house €2,000 will not cover it.
Ask any installer for the room by room heat loss calculation and the proposed flow temperature before you compare prices. Two quotes that both say "8.5 kW air to water" can be doing completely different amounts of work behind the walls.
The good end is very good. A homeowner in Claregalway runs his entire house, hot water, all appliances and two electric cars on about €2,500 a year after taking a 1980s bungalow from D to A over several years. A Roscrea household replaced about €1,000 of oil with about €650 of electricity and had condensation and mould in north facing bedrooms clear up. A Co Tipperary household cut total heating spend 58 per cent, from €2,000 of oil and solid fuel plus €1,000 of electricity down to €1,750 of electricity only.
The bad end is bad. An Offaly homeowner with a system installed in 2018 reported winter heating bills exceeding his mortgage payment in more than one month. A new build owner reported a single two month electricity bill over €1,000. Laois local authority tenants who received heat pumps in a council retrofit reported running costs close to their rent, with systems that must stay constantly on and no practical control over the cost. In every one of those cases the driver is the electricity unit price and how the house is run, not the equipment.
The most useful account we found has meters behind it. A 1930s three bed terrace taken to A2 saw gas fall from 5,000 to 6,000 kWh a year to about 600 kWh for cooking only, while electricity rose from about 1,000 kWh to between 2,200 and 2,600 kWh. His conclusion, posted as an anonymous forum account: "It will never pay for itself in terms of reducing bills." He also said the house is far more comfortable. Both halves of that are worth taking seriously.
A technical assessment, required for homes built before 2007 unless you already have a valid BER showing an acceptable heat loss indicator. SEAI grant aids €200 of it, and only alongside the heat pump grant. One documented One Stop Shop charged €775 for a technical assessment before the homeowner had decided anything.
A post works BER, which is mandatory. Median cost €245 to €280, with a €50 grant.
Space. The hot water cylinder that comes with a heat pump is larger than the one you have. One Dublin homeowner lost the corner of a bedroom she used as an office because the cylinder and plumbing did not fit the space allowed for them.
Electrical work. The same homeowner found her wiring was so old the whole house had to be rewired before retrofit could begin. That is not an energy upgrade and no grant reaches it.
Ask for the gross cost and the grant separately. Bundled quotes usually show a net figure with the grant already taken off, and you cannot compare a net price to a gross one.
Ask what heat loss indicator the house is assumed to achieve after the works, and what happens to the price if it does not get there. That number is what stands between you and the grant.
Ask which radiators are being replaced, whether pipework is being changed, and what the design flow temperature is. Then ask what the annual electricity estimate is at that flow temperature and what unit rate it assumes.
Get quotes from installers who do this weekly rather than occasionally. You can start with heat pump installers by county.
Tell us your county and we will introduce SEAI registered heat pump installers covering your area. No cost, no obligation.
SEAI's completion data for January to June 2026 puts the median installed cost at €17,000 for a detached house, €16,741 for a semi-detached, €16,000 for a mid terrace and €9,025 for an apartment. With the €12,500 grant that leaves €3,500 to €4,500 to pay on a house.
A fixed €12,500 for a house since 3 February 2026, made up of €6,500 for the heat pump, €2,000 for radiators and pipework and a €4,000 renewable heating bonus for coming off fossil or solid fuel. Apartments get up to €9,500. Air to air systems attract €3,500.
Because the grant requires a heat loss indicator of 2.3 W per K per square metre or better, and most older Irish houses need insulation, airtightness and sometimes windows to get there. Four documented Tipperary installations that included that fabric work ran €17,900 to €26,500 including VAT on houses of 165 to 210 square metres.
Sometimes substantially, sometimes not at all. Documented Irish outcomes range from a household running a whole house and two electric cars on €2,500 a year, to an Offaly homeowner whose winter heating bills exceeded his mortgage payment. The one metered account we found reported gas falling from about 5,500 kWh to 600 kWh while electricity rose from 1,000 kWh to about 2,400 kWh, and concluded it would never pay for itself on bills.
For homes built before 2007, yes, unless you have a valid BER that already shows a heat loss indicator of 2.3 or better. SEAI grant aids €200 towards it, payable only alongside the heat pump grant. One documented quote charged €775 for the assessment before any decision was made.
Usually some of them. A heat pump runs at a lower flow temperature than a boiler, so radiators have to be resized room by room, and micro-bore pipework often has to be replaced. The €12,500 grant includes €2,000 towards exactly this work.
Only if your house already meets the heat loss threshold, which mainly means homes built from the mid 2000s onwards. If it does not, you are looking at a fabric project first. One Waterford homeowner skipped heat pumps entirely for that reason and fitted infrared panels at €3,600 including VAT instead.
Checked against the official pages on 27 August 2026. Grant terms change, so confirm current amounts with SEAI or your installer before you commit.