Underfloor Heating Systems: Costs, Price per m² and How to Choose

What Is Underfloor Heating and How Does It Work?

Underfloor heating in homes comes in two types:

• Water-based (hydronic) system: Heating pipe is laid at even spacing on top of an insulation board and covered with screed. Hot water from the boiler or heat pump is distributed to the circuits through a manifold; the water circulating in the pipes gives its heat to the screed, and the screed gives it to the room.
• Electric system: Heating cables or film are used instead of pipes. No boiler or manifold is needed; running costs depend directly on electricity consumption.

Because heat spreads from the whole floor, there are no distinct hot and cold zones in the room. In this article we mainly cover the water-based system with a manifold.

Radiators or Underfloor Heating?

A radiator delivers heat from specific points; underfloor heating turns the entire floor into a large heating surface. Because the heating surface is large, it can deliver the same heat at a lower water temperature.

The low water temperature makes underfloor heating compatible with heat sources that are efficient at low temperatures, such as condensing boilers and heat pumps. Whether running costs will be lower than with radiators, however, depends on the building insulation, the heat source and usage habits; there is no fixed savings rate that applies to every project.

What Determines the Cost per m²?

The cost per square meter of underfloor heating is not fixed. Even two apartments of the same size can cost differently when pipe spacing, floor covering, heat source and controls differ. That is why ready-made “price per m² lists” found online are often misleading. The main cost items are:

Some items, such as the manifold, connections and design work, do not depend on the area. In small areas these fixed costs weigh more heavily per square meter and the unit cost rises; as the area grows, the share per square meter falls. A reliable cost figure requires a site survey and a project-based calculation.

How is the pipe length calculated?

Pipe length is one of the main cost items and is found with a simple calculation: pipe length per square meter is the inverse of the laying spacing. At 10 cm spacing you need 1 ÷ 0.10 = 10 m/m² of pipe, at 15 cm about 6.7 m/m². Multiply this by the net area to get the total pipe length, and the total pipe length tells you how many manifold circuits you need. Built-in cabinets, fixed furniture and areas under walls are not included in the net area.

To do the calculation room by room, use our underfloor heating calculation and cost page; pipes, manifolds and fittings are listed in our underfloor heating products category. This is a preliminary estimate; a final design requires a room-by-room heat loss calculation and a circuit layout.

What to Consider in the Total Cost

A sound cost estimate looks not only at the installation price but also at the costs the system will generate over the years:

• Installation cost: The sum of the items above; no firm figure can be given without a site survey and a design.
• Running cost: Depends on the efficiency of the heat source, energy prices, building insulation and the desired indoor temperature.
• Maintenance: A hydronic system needs regular checks of the manifold, pump and heat source; if the flow balance is lost, rooms heat unevenly.
• Metering in buildings with central heating: A heat cost allocator is mounted on the radiator surface, so it cannot be used with underfloor heating. In these apartments consumption is measured with a heat meter installed at the apartment inlet, and heating costs are shared according to this measurement. For how a heat meter works, see our What Is a Heat Meter? guide; for consumption-based allocation, see our heat cost allocation service.

Smart Thermostats and Room-by-Room Control

In hydronic underfloor heating, room-by-room control works by having the thermostat in each room open and close the actuator (motorized valve) of that room’s circuit on the manifold. Smart thermostats add time programs and remote access. This way unused rooms are not heated unnecessarily and each room is kept at the desired temperature. Since the savings depend on usage habits and the building, it would be wrong to quote a fixed rate.

Keep in mind that underfloor heating responds slowly: a steady temperature program suits these systems better than frequent switching on and off.

Flow Balancing and Manifold Selection

Each circuit has a different length and heat demand. If the flow is not balanced at the manifold, short circuits overheat while long circuits do not heat enough. Manifolds with flow meters make sure each circuit receives as much water as it needs. For the role of the manifold, see our What Does a Manifold with Flow Meters Do? page; for step-by-step adjustment, see our How to Adjust a Manifold with Flow Meters guide.

How to Choose the Floor Covering

Heat passes through the screed and reaches the room through the floor covering; the lower the thermal resistance of the covering, the more easily the system delivers heat.

• Ceramic tile and natural stone: They conduct heat well and are the easiest coverings to use with underfloor heating.
• Laminate and parquet: They can be used, but choose products the manufacturer declares suitable for underfloor heating and observe the manufacturer’s temperature limits.
• Carpet and thick floor coverings: They noticeably reduce heat transfer and must be taken into account in the design.

Brand or Installation Quality?

When researching underfloor heating you will come across well-known brands such as Rehau and Vaillant. Choosing quality pipes, manifolds and controls matters; but the system’s performance is determined as much by the heat loss calculation, the circuit layout, correct pipe laying and the flow balancing done at commissioning as by the brand. A poorly designed system heats unevenly even when built with good products.

How to Choose an Installer

• Do they survey the site and prepare a room-by-room heat loss calculation and circuit layout?
• Does the quote list pipe length, number of circuits, manifold type, insulation and controls separately?
• Do they run a pressure test after laying the pipes and before pouring the screed?
• Do they balance the manifold flows at commissioning?
• Do they offer a warranty and after-sales support, and can they show reference projects?

Contact us for help with material selection, or browse the products in our underfloor heating products category.