Radiators or underfloor heating? A comprehensive comparison for a family home in 2026
When you are building a new family home or renovating an older one, one of the most important decisions you have to make is the choice of heating system. And this is exactly where most people find themselves at a crossroads: radiators or underfloor heating? Both solutions have their passionate advocates and their critics. Both make sense – but not always for the same type of house, energy source or lifestyle.
In this article we take a really detailed look at both systems. We will not shy away from figures, specific real-world examples or uncomfortable truths. You will read what matters when choosing, what the true costs are, where each system excels and where it falls short. If you are looking for an answer to the question of which heating is right for you, you are in the right place.
How radiators work – the basics you need to understand
A radiator is a heat exchanger. Hot water (or an electrically heated element) warms the metal, which gives off heat to the room in two ways: by convection (air movement) and by radiation (infrared radiation). Most ordinary steel panel radiators work mainly by convection – they heat the air, which rises and circulates around the room. Cast iron radiators and bathroom towel radiators radiate more.
In a hydronic (wet) heating system, the boiler heats water, which circulates through pipes to the individual radiators and returns. The water temperature in a conventional system is between 60 and 80 °C (a so-called high-temperature system). Modern condensing boilers and heat pumps work more efficiently at lower temperatures – 45 to 55 °C.
Every radiator can be fitted with a thermostatic radiator valve, which regulates the water flow and therefore the output of the radiator. For example, the double-regulating thermostatic radiator valve – 1/2"xEK (angle) allows not only temperature control but also hydraulic balancing of the whole system – which, with several radiators in a house, is absolutely crucial for even heating.
Simplified diagram of a wet heating system with radiators and thermostatic radiator valves
How underfloor heating works – radiant heat from below
Underfloor heating (UFH for short) works on the principle of radiation. Pipes carrying warm water (or electric cables/mats) are laid in the floor construction. The whole floor becomes a large-area heat emitter that radiates infrared heat upwards. The floor surface temperature is between 24 and 29 °C – genuinely pleasant to walk on barefoot.
It is precisely the large radiating surface that is key. Because heat output = area × temperature difference, underfloor heating can heat efficiently at a much lower water temperature than radiators. Wet underfloor heating works ideally at a water temperature of 30–45 °C. This has a huge impact on the efficiency of modern heat pumps and condensing boilers.
Electric underfloor heating (a cable mat under tiles or an infrared film under a floating floor) works in the same way – only the heat source is electrical resistance instead of water. It is simpler to install, but running on electricity usually costs more than running a heat pump.
Layers of an underfloor heating construction and the direction of heat radiation
Radiators vs. underfloor heating – an overview of the key differences
Before we dive into the details, let us take a quick overview. The following table summarises the most important differences between the two systems so that you can get your bearings straight away.
| Criterion | Radiators | Underfloor heating |
|---|---|---|
| Water temperature (wet system) | 55–80 °C | 30–45 °C |
| Room warm-up time | 15–30 minutes | 1–3 hours |
| Comfort (perception of warmth) | medium | high (even warmth) |
| Installation cost (typical 150 m² house) | 3 000–7 000 € | 6 000–14 000 € |
| Efficiency with a heat pump (COP) | lower (higher water temperature) | significantly higher (low water temperature) |
| Ease of retrofitting during renovation | easy | demanding (floors must be broken out) |
| Room-by-room control | excellent (thermostatic radiator valves) | good (manifold + thermostatic heads) |
| Visibility of the equipment | yes, visible on the wall | hidden in the floor |
| Suitability for allergy sufferers | medium (air movement) | excellent (no dust convection) |
| Service life | 20–30 years | 30–50 years |
Where radiators still make sense
Although underfloor heating gets a great deal of attention in the media these days, radiators are by no means an outdated technology. There are several situations where they are clearly the better choice, or at least the more pragmatic solution.
Renovating old houses
Imagine a typical brick-built house from the 1980s with concrete floors. Installing underfloor heating would mean breaking out the existing floors, new thermal insulation, a new screed layer with pipes and new floor coverings. The cost of this work alone in a 150 m² house can climb to €8,000–15,000 – before the system itself. What is more, the building work takes weeks and the house is uninhabitable during that time.
In a renovation like this it is far more sensible to replace the old cast iron column radiators with modern steel panel radiators, fit thermostatic radiator valves and, if need be, upgrade the boiler. All for a fraction of the price and in a few days' work.
Rooms with a higher ceiling or an irregular shape
In reception rooms with high ceilings (3.5 m or more), in halls or in rooms with a lot of fitted furniture (where the output of underfloor heating would be limited by the covered area), radiators are more practical. You can place a radiator under a window, where it compensates precisely for the heat lost through the glazing.
Fast response to temperature changes
Do you have a cottage you visit only at weekends? Or an office where you need to heat the space quickly before people arrive? A radiator warms a room in 15–30 minutes. Underfloor heating needs 1–3 hours to reach the required air temperature. For properties with intermittent heating, radiators are clearly more suitable.
Combination with a gas boiler or a back-boiler stove
A conventional gas condensing boiler also works efficiently at higher water temperatures (55–70 °C), at which radiators deliver their full output. If you have such a boiler and do not plan to switch to a heat pump, investing in underfloor heating (with its low-temperature operation) will not pay off – you will not achieve any significant energy saving, but you will pay considerably more for installation.
Where underfloor heating excels
Underfloor heating is not just a passing fad. In the right conditions it brings real and measurable benefits – in comfort, hygiene and economy.
New builds with a heat pump
This is the ideal combination for the 21st century. A heat pump (air-to-water or ground-source) works with a coefficient of performance (COP) of 3–5, which means that it produces 3–5 kWh of heat from 1 kWh of electricity. But this applies only when the temperature difference between the heat source (outdoor air or the ground) and the heated water is as small as possible. Underfloor heating, where water at 35–40 °C is enough instead of 70 °C, dramatically increases the COP of the heat pump.
A real-world example: a 150 m² house, low-energy standard, heat loss approx. 6 kW. With a heat pump and underfloor heating at a COP of 4.2 = annual electricity consumption of approx. 4,000–5,000 kWh, costing approx. €560–700/year on the D6 tariff (0.14 €/kWh). With a gas boiler and radiators (at a gas price of 0.08 €/kWh and 95% efficiency): approx. 7,000–8,500 kWh of gas, approx. €560–680/year. Economically the two are currently close – but the heat pump does not depend on the price of gas and has zero CO₂ emissions when run on renewable electricity.
Comfort and health – the argument for allergy sufferers
Convection heating (radiators) moves air around the room. The air lifts dust, mould and dust mites, which can be a problem for people with allergies or asthma. Radiant underfloor heating does not move the air – heat passes directly from the warmed surface into the room. The result is cleaner air and a lower concentration of dust in the breathing zone.
In addition, with radiant heating the air temperature at floor level and at the ceiling differs only minimally (1–2 °C). With convection heating the difference between ceiling and floor can be 5–8 °C. The body perceives radiant heat as more pleasant, so with underfloor heating a lower air temperature (by 1–2 °C) is enough for the same feeling of thermal comfort. This also helps to save energy.
Aesthetics with no visible radiators
A modern minimalist interior, large floor-to-ceiling windows, open-plan spaces – in a concept like this, radiators are aesthetically unwelcome. Underfloor heating is hidden and invisible, leaving the walls free for furniture, windows and art. For many clients this is the deciding argument.
Supplementary electric heating – when it has its place
Neither radiators nor underfloor heating are the only answer to every situation. Supplementary electric heaters play an important role in practice – especially in spring and autumn, for heating smaller spaces or where installing a whole system would not be economical.
An interesting category is modern WIFI infrared panels and electric heaters with smart control. They allow the temperature to be set precisely by the hour, day and week directly from a smartphone, with no need for any pipework at all.
WIFI heater H+h WIFI 150W – ideal for small rooms, controlled from a smartphone
For example, the WIFI heater H+h WIFI 150W is designed for bathrooms, dressing rooms or small studies (up to approx. 5–8 m²). There is no pipework to install and no hydraulics to worry about – you simply fix it to the wall and connect it to your home WiFi network. These heaters are particularly practical in old houses where you have replaced the radiators in most rooms but want to top up the heating in the bathroom or dressing room independently.
WIFI heater H+h WIFI 300W – suitable for medium-sized rooms, e.g. a child's bedroom or a study
For larger rooms (10–15 m²), consider the WIFI heater H+h WIFI 600W, and for a living room or an open-plan kitchen-living room even the H+h WIFI 900W or H+h WIFI 1200W.
WIFI heater H+h WIFI 600W – an effective supplement for medium-sized rooms
WIFI heater H+h WIFI 900W – a powerful solution for spacious rooms
These appliances are also useful as a temporary solution during major renovations – when you do not yet have a working heating system but need to heat a workspace or a finished room. Or as a safeguard in garages and plant rooms, where installing pipework would not make economic sense.
Combining both systems – the hybrid approach
In practice, the choice is not always "either-or". Many modern family homes combine both systems according to the purpose of the rooms:
- Ground floor (living room, dining room, kitchen) – underfloor heating: a large area, open-plan space and the place where the family spends most of its time, where comfort and aesthetics come fully into their own.
- Upper floor (bedrooms, children's rooms) – low panel radiators or designer radiators: cheaper installation and fast control (in a bedroom you want it cooler at night and warm quickly in the morning).
- Bathroom – an electric towel radiator or a WIFI heater: independent of the main system, used as needed.
- Garage, workshop – electric heaters with WIFI control: only when needed.
This hybrid approach is very common today and makes a great deal of economic sense. You do not have to build the whole house around one system – choose the best tool for each purpose.
Indicative installation costs for a 150 m² house by chosen system (excluding boiler/heat pump)
Temperature control – thermostatic valves and smart systems
Whether you choose radiators or underfloor heating, temperature control is fundamental to both comfort and energy consumption. A well-designed control system can cut energy consumption by 15–25% compared with a simple on/off controller.
With radiators, the basis is the thermostatic radiator valve. Modern electronic thermostatic heads communicate with a central controller, allow temperatures to be programmed by the hour, day and week, and some connect directly to a smart home system via Zigbee or Z-Wave. Hydraulic balancing of the system is another important element – the double-regulating angle thermostatic radiator valve 1/2"xEK lets you set the flow precisely for each radiator individually, ensuring even heating throughout the house without some rooms overheating while others stay cold.
With underfloor heating, the temperature is controlled by thermostatic heads on the manifold – separately for each room. An electric actuator opens or closes the flow for the circuit in question. Combined with room thermostats (and increasingly with WIFI thermostats or systems such as Honeywell Evohome, Danfoss Link or simpler OpenTherm controllers), this creates a system in which every room has its own temperature.
In practice, underfloor heating control is a little "lazier" – the thermostat responds, but 30–90 minutes may pass while the floor heats up or cools down. That is why, with underfloor heating, it is important to set the right heating curves and not try to change the temperature by several degrees every hour.
The legislative context in 2026 – energy performance of buildings
In Slovakia, Act No. 555/2005 Coll. on the Energy Performance of Buildings has applied since 2013 (with updates in 2019 and 2022). Since 2021, all newly built family homes must meet the nearly zero-energy standard (NZEB – Nearly Zero Energy Building). In practice this means a maximum primary energy consumption of 54 kWh/(m²·year) for a family home.
This standard effectively pushes new houses towards heat pumps and low-temperature heating systems – that is, underfloor heating or low-temperature radiators (so-called design radiators with a larger surface area, which work efficiently even at 45 °C). Conventional radiators with a high-temperature boiler (a gas boiler at 70 °C) are usually not enough to meet NZEB in new builds – the system's primary energy consumption is too high.
Less stringent criteria apply to renovations of existing houses, but here too, subsidies for insulation and boiler replacement (the Zelená domácnostiam programme, running since 2024 and continuing in 2026) are tied to achieving a certain energy class. A heat pump combined with underfloor heating, or low-temperature radiators combined with a heat pump, is in most cases a condition for obtaining support from the state building renovation programme.
Practice and experience – what homeowners say
Case 1: 140 m² new build, low-energy house, heat pump + underfloor heating
The Novák family from near Žilina built a 140 m² single-storey passive house in 2023. They chose an air-to-water heat pump (8 kW) and wet underfloor heating throughout the ground floor. Installing the underfloor heating cost €9,800 (pipes, manifold, thermostatic actuators, screed), and the heat pump a further €7,500. Annual costs for heating and domestic hot water: €680 at an average electricity price of 0.17 €/kWh. Neighbours in a comparable house with a gas boiler and radiators pay €900–1,100 a year for gas. The difference is not dramatic, but the Nováks stress comfort above all: "We walk barefoot around the whole house all winter, the air isn't dry and there is far less dusting to do. I have allergies, and in the first year I had noticeably fewer problems."
Case 2: Renovation of a 180 m² brick-built house from 1985, radiator replacement
Mrs Krajčíová in Bratislava renovated the family house she inherited from her parents. She replaced the old cast iron radiators with modern KORAD and Zehnder steel panel radiators, added thermostatic radiator valves to each one and replaced the boiler with a gas condensing boiler. Total cost: €6,200 (radiators + valves and fittings + labour). In this case underfloor heating would have meant breaking out all the floors and a further 3 months of renovation – at an estimated cost of €18,000–22,000. The decision? Clear-cut. "I didn't want to live on a building site for a year. The new radiators look lovely, the controls work perfectly and the house is finally heated evenly."
Case 3: A hybrid solution – underfloor heating downstairs, radiators upstairs
The Horvát family from Košice built a 200 m² two-storey house. Ground floor (80 m²: kitchen, dining room, living room, hallway) – wet underfloor heating. Upper floor (120 m²: 4 bedrooms, 2 bathrooms, study) – low-temperature panel radiators with electric thermostatic heads. A 10 kW ground-source heat pump feeds both circuits. The water temperature is 35 °C for the underfloor heating and 48 °C for the radiators (low-temperature models). "It works brilliantly. In the morning before we get up, we set the thermostat upstairs to 21 °C and it is warm within 20 minutes. During the day the ground floor is pleasantly warm without us having to adjust anything. Everyone has their own temperature in their room."
Choosing floor coverings for underfloor heating
An important but often underestimated aspect: not every floor covering is suitable over underfloor heating. The thermal resistance (R-value) of the floor covering directly affects the efficiency of the whole system.
- Ceramic tiles and stone – ideal, low thermal resistance (R = 0.01–0.03 m²K/W), excellent heat transfer. Bathrooms, kitchens, hallways.
- Vinyl flooring (LVT) – suitable when marked "suitable for underfloor heating". Watch the resistance value – max. R = 0.075 m²K/W.
- Wooden parquet, laminate – conditionally suitable. It must be approved for underfloor heating, with a maximum surface temperature of 27 °C. Solid wood is less suitable (it cracks as moisture levels change).
- Carpets – unsuitable, or only with low thermal resistance. A thick carpet can block heat transfer completely, and the system then has to run at a higher output.
- Epoxy and polyurethane screeds – excellent, even, no problems at all.
A practical tip: if you are planning carpet or solid wood in some rooms, tell your heating designer – they must take it into account when sizing the pipe spacing (closer spacing = higher output per m²) or the output of the whole circuit.
The most common mistakes when choosing and installing a heating system
After years of practice and conversations with installers and homeowners, the same mistakes keep recurring:
- Underestimating hydraulic balancing – without correctly set regulating valves, the system will have hot and cold rooms at the same time. A double-regulating thermostatic radiator valve on every radiator is not a luxury but a necessity.
- Underfloor heating in a poorly insulated house – with high heat losses (an old uninsulated house), underfloor heating cannot cover the heat demand. Insulation first, then a new system.
- Too steep a heating curve on the boiler – owners with underfloor heating sometimes set the boiler or heat pump to too high a water temperature (60 °C) in the belief that it will be "warmer". The result: cracking parquet, overheated rooms and increased consumption.
- Forgetting about the manifold for underfloor heating – the manifold with regulating valves and thermostatic actuators must be correctly sized and accessible (in a manifold cabinet). Do not build it into a wall without an access panel.
- Radiators without air vents – air in the system reduces radiator output and causes noise (gurgling). Every radiator must have an air vent, and the system must be correctly filled and bled.
- Ignoring the warm-up time of underfloor heating – underfloor heating controls must be set well ahead of time. If you want a warm bathroom at 7:00 in the morning, the thermostat must respond by 5:00–5:30 at the latest.
Running costs in 2026 – current figures
Energy prices in Slovakia in 2026: electricity for households (D1 tariff) is around 0.16–0.19 €/kWh, natural gas around 0.06–0.09 €/kWh (depending on supplier and contract), and wood pellets €280–380 per tonne. These values are decisive for the economics of your choice.
For a specific example – a well-insulated 150 m² family home (energy class B) with a heat loss of 7 kW:
| Heating system | Annual energy consumption | Estimated cost/year |
|---|---|---|
| Gas boiler + radiators (η=95%) | approx. 8,500 kWh of gas | 510 – 765 € |
| Gas boiler + underfloor heating | approx. 7,800 kWh of gas | 468 – 702 € |
| Air-to-water heat pump (COP 3.5) + radiators (55°C) | approx. 2,800 kWh of electricity | 448 – 532 € |
| Air-to-water heat pump (COP 4.2) + underfloor heating (35°C) | approx. 2,300 kWh of electricity | 368 – 437 € |
| Pellet boiler + radiators | approx. 2,200 kg of pellets | 616 – 836 € |
The table shows that the lowest running costs are achieved by the combination of a heat pump and underfloor heating. But even a heat pump with low-temperature radiators (55 °C instead of 70 °C) is significantly better than a gas boiler. However, the investment costs of a heat pump with underfloor heating are €10,000–20,000 higher than for a gas boiler with radiators, so the payback needs to be calculated individually – it depends on energy prices, the service life of the equipment and the subsidies available.
Frequently asked questions (FAQ)
Can I install underfloor heating in an old house without breaking out the floors?
Conventional wet underfloor heating (pipes in a concrete screed) requires the floor to be raised by 8–12 cm, which in the vast majority of old houses means completely breaking out the existing construction. However, there are thin systems with aluminium plates (dry underfloor heating systems) where the build-up is only 2–4 cm – usable in renovations where the ceiling height allows. These systems are more expensive and have a lower output, but they can be a compromise solution. Electric infrared film (e.g. under laminate) is thinner still and the easiest to install.
Is underfloor heating suitable for a bathroom?
Yes, the bathroom is one of the most ideal rooms for underfloor heating – tiles have low thermal resistance, comfort is at its greatest (a warm floor underfoot after a shower) and bathrooms do not usually contain large pieces of furniture that would block the output. You can supplement the output of bathroom underfloor heating with an electric towel radiator (for drying towels), or with a WIFI heater for a quick top-up in spring and autumn.
Can I have underfloor heating under wooden parquet?
Yes, but with limitations. Wood and moisture do not get on particularly well – with repeated heating and cooling, solid wood can crack or lift. Multi-layer (engineered) parquet or laminate marked as suitable for underfloor heating (thermal resistance max. 0.10–0.15 m²K/W) is a safer choice. The maximum surface temperature of a wooden floor should not exceed 27 °C. Consult both the parquet supplier and the heating system supplier before you buy.
Is it true that underfloor heating does not stir up dust?
Yes, radiant systems (including underfloor heating) do not move the air as vigorously as convection heating (radiators). Dust, dust mites and mould spores are not stirred up. For allergy sufferers and people with asthma this is a real and measurable benefit. Combined with controlled ventilation (heat recovery), the result is even better – clean, warm air with no swirling dust.
How much does it cost to replace the radiators in a typical house?
As a guide: for each radiator (a new type 22 steel panel radiator, size 600×1000 mm, output approx. 1400 W) you will pay €80–180 for the radiator itself, €20–50 for the valves and fittings (thermostatic radiator valve, lockshield valve, air vent), plus approx. €80–150 for the installer's labour. In total, approx. €180–380 per radiator including labour. A house with 8–10 radiators = €1,500–3,800 for radiators and fittings, plus any replacement of pipework and the boiler. Complete renovation of the system in a 150 m² house including a condensing boiler: €5,000–10,000.
Can a WIFI electric heater replace a radiator?
As a supplementary or stand-alone solution for smaller spaces – yes. The H+h series WIFI heaters are fully fledged electric heaters with precise control and remote operation. For a bathroom, dressing room or study they can be a full replacement for a radiator, especially if these rooms are not connected to the central heating system or are used in a different pattern. For all-day operation in a larger room, running costs are higher than with a wet system (electricity is more expensive), but the investment costs are negligible compared with installing pipework.
Conclusion: how do you make the right decision?
There is no universal answer to the question of which is better – radiators or underfloor heating. There is only the right answer for your particular house, your budget, your heat source and your lifestyle.
If you are building a new low-energy or passive house and planning a heat pump – underfloor heating (at least on the ground floor) is almost always the right choice. Maximum comfort, the lowest running consumption and decades of trouble-free operation.
If you are renovating an older house and do not want to break out the floors – modern panel radiators with thermostatic radiator valves and a condensing boiler or heat pump are a sensible, economically justified solution. New radiators are attractive, efficient and, with good controls, very economical.
If you are looking for a supplementary solution for a particular room, cottage, office or temporary heating – WIFI electric heaters such as the H+h WIFI series are a convenient and affordable choice with minimal installation and maximum flexibility.
And if you are still unsure, discuss the project with a specialist – a heating designer. A good heating system design (heat loss calculation, sizing, hydraulic balancing) costs a few hundred euros, but it will save you thousands on an incorrectly sized system and years of discomfort with underheated rooms or an overheated hallway. Heating is a long-term investment – it pays to get it right from the start.
Do you have a question about this topic?
Can't decide, or dealing with a specific situation in your home? Write to us - we will be happy to advise.