Underfloor Heating in Ireland: Cost per m², Running Costs and Grants (2026)

Last updated: September 2026
Underfloor heating is standard in Irish new builds and increasingly the first thing people ask about when planning an extension or a deep retrofit - and the answer to "what does it cost?" is €60-90 per square metre supplied and fitted for a wet system in a new floor, €70-110 for a low-profile retrofit overlay, and €50-75 for electric mats in a bathroom, before screed and flooring. A whole 3-bed house comes to €6,000-12,000; a single bathroom on electric mats €600-1,100. This guide covers wet versus electric, installed and running costs in 2026, what it does to your floor height and flooring choice, the grant position, and why underfloor heating and a heat pump belong together.

⚡ Quick Summary

🌿 Wet (water) systems run warm water through pipes in or under the floor from a boiler or heat pump: the whole-house option, €60-110/m² installed plus €400-900 per manifold.
🌿 Electric mats are cheap to fit (€50-75/m², one day under the tiler) and dear to run - about three times the cost per unit of heat of a wet system on a heat pump. Bathrooms and single rooms only.
🌿 Running cost: a 20 m² room on wet underfloor heating fed by a heat pump costs roughly €120 a winter; the same room on electric mats about €400 at 35c/kWh.
🌿 Flow temperature is the point: underfloor heating runs at 35-45°C, where a heat pump's efficiency (COP 3.4-3.8) is highest; radiators want 55-70°C.
🌿 Grants: none for underfloor heating on its own. Up to €2,000 of the €12,500 SEAI heat pump grant covers new radiators or underfloor heating as the distribution upgrade; a floor insulation grant of €3,500 exists through the One Stop Shop route.
🌿 Floors: tile and stone best (surface up to 29°C), engineered wood and vinyl fine (27°C limit), carpet only with underlay under 2.5 tog. Retrofit overlays add 15-40 mm to floor height.

💧 Wet vs Electric: How Each Works and Where It Belongs

🌿 Wet underfloor heating is a network of plastic pipe loops - in a 65-75 mm screed in a new build, or in grooved insulation panels or a 15-20 mm overlay board in a retrofit - fed from a manifold that blends the boiler or heat pump water down to 25-45°C. Each room's loop has its own thermostat and actuator. It is the same heat as radiators delivered through a bigger, cooler surface, so it costs no more to run than radiators on the same boiler, and a good deal less on a heat pump. Pipes have a design life of 50 years or more.
🌿 Electric underfloor heating is a heating mat or loose cable (usually 150 W/m², 110-240 W/m² available) laid in tile adhesive under the floor finish with a floor-sensor thermostat. Fast to fit, no manifold, no plumbing - but it is direct electric heat at 35-38c per kWh, against 10-14c for the same heat from a heat pump or gas. The industry's own guidance is small, occasionally used rooms: a bathroom, an en suite, a porch.

The practical split: wet for the ground floor of a new build or extension and for whole-house retrofits done alongside a heat pump; electric for the bathroom floor you want warm for 40 minutes a morning.

💶 Installed Costs in Ireland (2026)

🌿 Wet, new build or extension (pipe in screed): €60-90/m² supply and fit. A typical 3-bed semi's ground floor: €3,000-6,000 for the heating system, more with the whole house done. Real 2024 quote seen: €2,300 including VAT for 55 m² of pipework, manifold, valves and pumps.
🌿 Wet, retrofit overlay: from €70/m² and up to €110/m² for low-profile systems that sit on the existing floor; suspended timber floors take a timber overfloor system, old solid floors get a foil insulation layer first.
🌿 Manifold and zoning: €400-900 per manifold, plus thermostats and wiring centre for each zone.
🌿 Whole house, 100-150 m²: €6,000-13,500 all-in for the heating side, per installer guides; a heat pump plus underfloor package from about €8,500 in Dublin quotes.
🌿 Electric mats: materials €60-110 per m² mat kit (a 5 m² kit €175-290, 10 m² €295-510), thermostat €60-150, electrician €150-300 - a bathroom lands at €600-1,100 fitted.
🌿 Not in those numbers: screed (€15-30/m² and 4-8 weeks to dry), floor insulation if needed (€30-60/m², or €3,000-12,000 for a full floor dig-out and rebuild), the floor finish, and the heat source itself.

The often-quoted "€18-26 per square metre" is a 2022 materials-only figure for the pipe stage of a new build. It is not what you will pay to have a floor heated.

🔹 Estimate your own installation and running cost

🔥 Running Costs and the Heat Pump Pairing

A well-insulated modern home needs only 20-30 W/m² of heat; an older retrofit may need double. Wet underfloor heating at a 40°C flow and 150 mm pipe spacing delivers 70-90 W/m², so it has headroom in either case.

The heat source sets the bill. An air-to-water heat pump running at 35°C flow achieves a COP around 3.8 - 3.8 kWh of heat per kWh of electricity - falling to about 3.0 at 45°C and 2.3 at 55°C; every 5°C off the flow temperature is worth roughly 10-15% on running cost. Radiators sized for a boiler need 55-70°C. That is why installers describe underfloor heating and a heat pump as the ideal pairing: a 100 m² house at 40 W/m² for 8 hours a day uses about 32 kWh of heat, which is €3.20 a day at 35c/kWh on a COP of 3.5, against €4.30 on gas or €5.00 on oil for the same heat. Our heat pump guide and air-to-water cost guide cover the rest.

Electric mats are the exception: at 150 W/m², a 5 m² bathroom for 2 hours a day is 1.5 kWh, about 53c a day or €95 over a 180-day season at full power - fine for a bathroom, ruinous for a sitting room, where our electric heater guide numbers apply.

🔹 Response time and controls

Heat buried in a screed takes 2-3 hours to come up and holds heat for hours after; overlay systems respond in 30-60 minutes; electric mats in 30-90. Run screeded systems on a low continuous setting with setback overnight rather than on-off, zone it room by room (bedrooms 18°C, living 21°C, bathrooms 24°C) and use a weather-compensating heat pump controller. Bring a new screed up 1-2°C a day at commissioning or it can crack.

🧱 Floors, Insulation and Build-Up

🌿 Insulation under the pipes is not optional: Part L requires a floor U-value of 0.15 W/m²K in a new dwelling heated by underfloor heating (0.18 otherwise) and 0.45 for a retrofitted existing floor. Pipes over an uninsulated slab heat the ground. Up to 10% of a home's heat is lost through the floor even without heating it directly.
🌿 Build-up height: new build 65-95 mm of screed on 100-150 mm of insulation; retrofit overlay 15-40 mm plus the floor finish. Check door thresholds, skirting and stair bottoms before you commit.
🌿 Floor finishes: tile, porcelain and stone conduct best (surface up to 29°C); engineered wood 14-18 mm and LVT/vinyl are fine (27°C limit); solid timber over 25 mm and thick carpet are poor - carpet plus underlay must stay under 2.5 tog, ideally under 1.5 with a heat pump.
🌿 Timeline: pipework 2-4 days for a single storey, then 4-8 weeks screed drying before the system is commissioned; electric mats one day.

💶 Grants and Loans

There is no SEAI grant for underfloor heating as a measure in its own right. Where it is funded is inside the heat pump grant (since February 2026: €6,500 for the unit, €2,000 for the central heating upgrade - "new radiators, underfloor heating or other required upgrades" - and a €4,000 Renewable Heat Bonus for replacing oil, gas or solid fuel; €12,500 in total for a house, €9,500 for an apartment). The home must have been built before 2021 and, if pre-2007, pass a technical assessment (€200 grant) or show a heat loss indicator of 2.3 or better. Floor insulation attracts a €3,500 grant through the One Stop Shop deep-retrofit route. The Home Energy Upgrade Loan (€5,000-75,000) can finance underfloor heating only as part of a grant-aided heat pump job. Full grant tables are in our SEAI grants guide and retrofitting guide.

⚖️ Is It Worth It?

🌿 Yes, almost always, in a new build, an extension, or a deep retrofit that is going to a heat pump anyway - the floor is open, the marginal cost over radiators is small, and it unlocks the lowest flow temperatures.
🌿 Often, for a ground-floor retrofit in a bungalow or a house being re-floored, if the floor can be insulated at the same time.
🌿 Rarely, to replace working radiators in an insulated house on a boiler: the running cost is the same, the comfort gain is real but the bill is €6,000+.
🌿 For bathrooms, electric mats at €600-1,100 are a comfort purchase that runs for pennies a day - just not the answer for the whole house.

⚠️ Common Mistakes to Avoid

🌿 Laying pipes on an uninsulated floor: a large share of the heat goes down. Insulate to 0.15-0.45 W/m²K first.
🌿 Electric mats as main heating: three times the running cost of a wet system on a heat pump.
🌿 Thick carpet or solid oak on top: a 3-tog carpet turns a heated floor into an insulated one.
🌿 Running it like radiators: screeded systems want low and steady, not off-and-blast.
🌿 Skipping the design: a quote should include a CAD pipe layout, a pressure-test certificate per circuit, commissioning instructions and a materials-and-workmanship warranty. "We'll run pipe at 200 mm centres everywhere" is not a design.
🌿 Forgetting the manifold needs a home: a utility room or press near the heat source, accessible for the pump and actuators.

❓ Frequently Asked Questions

🔹 How much does underfloor heating cost per square metre in Ireland?

Wet systems €60-90/m² in a new floor and €70-110/m² as a retrofit overlay, supplied and fitted; electric mats €50-75/m². Add screed, insulation and flooring.

🔹 Is underfloor heating expensive to run?

Wet underfloor heating costs the same as radiators on the same boiler and less on a heat pump - about €3.20 a day for a 100 m² house on a heat pump at 2026 rates. Electric mats cost 35-38c per kWh of heat, so keep them to small rooms.

🔹 Can you retrofit underfloor heating into an existing house?

Yes, with low-profile overlay systems that add 15-40 mm, or by digging out and re-laying the floor with insulation. The second is the better job and the bigger bill.

🔹 Does underfloor heating work with a gas boiler?

Yes, through a blending valve on the manifold that drops the water to 40-45°C. It works; it just does not get the efficiency bonus a heat pump does.

🔹 Is there an SEAI grant for underfloor heating?

Not on its own. Up to €2,000 of the heat pump grant covers the heat distribution upgrade, which can be underfloor heating.

🔹 What flooring can I put over it?

Tile, stone, porcelain, LVT and 14-18 mm engineered wood. Carpet only with combined underlay under 2.5 tog. Keep surface temperatures under 27°C for wood and vinyl, 29°C for tile.

📚 Related Guides

🌿 Heat Pumps
🌿 Air-to-Water Heat Pump Cost
🌿 Air-to-Air Heat Pumps
🌿 Heating Oil Prices
🌿 Heating Oil by County
🌿 HVO Fuel
🌿 Boiler Replacement Cost
🌿 Gas Boiler Service
🌿 Storage Heaters
👉 All guides and calculators

Climate Jargon Buster is an independent resource. Costs are indicative ranges from Irish installer guides and retailers, correct as of September 2026; grant amounts are set by the SEAI, with which we are not affiliated - check seai.ie and get a designed quote before committing.