Underfloor heating installation across Ireland

In 2026, supplying and installing wet (hydronic) underfloor heating in an Irish new build or extension costs €40 to €65 per m² for the pipework, manifold and room thermostats, or €65 to €95 per m² complete with 50mm pumped liquid screed. Low-profile 15mm–18mm retrofit overlay systems cost €85 to €125 per m², and electric heating mats for bathrooms cost €45 to €75 per m².

Yes. Low-profile retrofit overlay panels (15mm to 18mm total build-up) bond directly on top of your existing concrete slab or floor tiles and carry 12mm oxygen-barrier pipe in a thin fibre-reinforced levelling compound. Alternatively, if you have a sound 60mm+ sand-and-cement screed, dust-free diamond milling cuts 16mm pipe channels flush into the top of the existing slab with 0mm added floor height.

Hydronic underfloor heating paired with an air-to-water heat pump in Ireland is designed for a 35°C flow temperature (and 28°C–30°C return) at -3°C outdoor temperature. Running at 35°C instead of 50°C–55°C radiator temperatures boosts heat pump seasonal efficiency (SCOP) above 4.0 and cuts winter running costs to roughly 8.5c–9.8c per kWh of heat.

While SEAI does not grant-aid underfloor heating on a standalone fossil boiler, homeowners upgrading a pre-2021 property to an air-to-water heat pump can claim up to €14,500 under the SEAI Heat Pump System Grant (€11,500 for apartments), which includes up to €2,000 (€1,000 for apartments) specifically towards installing underfloor heating.

Wet hydronic pipework is the right choice for whole ground floors, extensions and open-plan renovations over 15 m² because its running cost on a heat pump or condensing boiler is three to four times lower than direct electricity. Electric heating mats (150W–200W/m²) are ideal for single bathrooms, en-suites and small upstairs wetrooms under 10 m² where 3.5mm–5mm thickness and low upfront installation cost matter most.

With a 50mm calcium-sulphate (anhydrite) or flowing cementitious liquid screed, you can walk on the floor after 24–48 hours and start the gentle EN 1264-4 commissioning heat-up cycle at 20°C–25°C after 7 days (compared with waiting 21–28 days on traditional hand-laid sand-and-cement screed).

For an air-to-water heat pump running at a 35°C flow temperature, 16mm pipe is normally clipped at 150mm centres across living areas and 100mm centres in bathrooms or high-heat-loss sunrooms. Individual 16mm loops are kept below 100 linear metres (roughly 14–15 m² per port), while 12mm low-profile retrofit pipe is clipped at 100mm–125mm centres with loops capped at 60–75 linear metres.

When a heat pump feeds an open-plan ground-floor underfloor heating manifold directly (and at least one or two zones remain open or weather-compensated), no blending mixing valve is needed because the heat pump already produces 30°C–38°C water. Mixing valves are only fitted when a 65°C–75°C gas or oil boiler feeds the manifold.

In a new build or full ground-floor dig-out, the insulation (120mm–150mm PIR) and screed (50mm liquid screed or 65mm–75mm sand-and-cement) are already part of the structural floor build-up, so the heating pipes add 0mm of extra height. In an existing room where you keep the concrete slab intact, a low-profile wet overlay system adds just 15mm to 18mm before tiles or wood, and an electric decoupling mat adds 3.5mm to 5.5mm.

Yes — dual-temperature hybrid systems are standard in Irish extensions and two-storey refurbishments. On a condensing gas or oil boiler, the upstairs radiators run at 60°C–70°C on Zone 1 while a thermostatic pump-and-mixing pack steps the downstairs manifold down to 40°C–45°C on Zone 2. On a heat pump, low-temperature aluminium or double-panel K2/K3 radiators upstairs run alongside the downstairs floor at 35°C–42°C.

For a 60 m² to 100 m² ground floor or extension, laying the perimeter strip, foil vapour membrane, 16mm pipe loops, manifold, and air/water pressure test takes 1 to 2 working days before the screed team pours. Low-profile retrofit overlay boards across a 40 m² kitchen-diner take 1 to 2 days including self-levelling compound, and a bathroom electric heating mat takes half a day before tiling.

Every hydronic loop is flushed clean of air, filled with water (or compressed air in freezing weather), and pressure-tested to 6 bar (twice normal operating pressure) in accordance with EN 1264-4. The manifold pressure gauge remains locked at 3 to 6 bar throughout the liquid screed pour so any accidental site damage is spotted immediately.