Floor Heating System Costs & Energy Usage

There is much you can do to have an impact on both installation and running costs for your floor heating system

The underfloor heating system at design stage:

Long, narrow or irregular shapes, expose more external wall surface for any given floor area, compared to something approaching a square shape. Two storey designs are even better.

If practicable, locate the garage on the Western side, providing a barrier against the afternoon sun to improve your summer comfort. Buildings in the Southern hemisphere should have good Northern exposure. With standard 600mm eaves, the sun will not contact the Northern glass in summer months, but will extend at least two metres into the room during winter.

Thermal insulation

Requirements for thermal insulation are now specified in the Building Code of Australia. These should be viewed as the minimum. To maintain warmth in a building, you are paying for the energy used to replace that which is lost through the walls, floor and ceiling. Glass areas are significant in heat loss and should not be unnecessarily large. Heavy, close fitting drapes will reduce this loss. Double glazing may also be considered, especially in the colder zones, or where noise reduction is desireable as well.

Floor heating hydronics and electrical system thermostatsFloor heating thermostats

With the energy loss being proportional to the average temperature difference between inside and outside, every degree we alter the thermostat affects our running cost by approximately 15% . With warm floors and no air circulation, we feel comfortable at a lower air temperature anyway. A key feature with the Heatec thermostats is the ability to program different running times and temperatures according to your daily shedule.

You take control!

The Heatec programmable thermostat can switch ON/OFF or between different temperature settings according to time of day, minimising your floor heating running cost. Although control is normally based on air temperature, the included floor sensor can be used as an overtemperature cutout if the floor becomes too warm. The use of this becomes necessary for temperature-sensitive flooring products such as timber. Using the floor sensor as the primary control can be problematic since our floor temperature requirements are linked to our general need for warmth, which changes frequently with the air temperature.


With the floor heating split into separately-controlled zones, you enjoy individual control of each area. A zone may be a single room, or group of adjoining areas. By having a separate control for each, you are controlling your energy consumption zone by zone.

Approximate running cost for electric floor heating


For an outline of electricity tariffs, it is suggested that you refer to: https://www.aer.gov.au/consumers/my-energy-bill/tariff-and-fees-explained

Small zones

With small zones such as single bathrooms or ensuites, the choice of tariff will have less impact because the electrical load is small and you should be making use of your Heatec programmable thermostat to limit the input hours. A room of around 7 square metres with 4 square metres of heated floor, will have around 600W of heating installed. If the average wintertime thermostat ON periods amount to 4 hours per day, this will cost $4.20 per week on an electricity tariff of 0.25 c/kWhr.

Larger areas:

Consider both the installation method and the electricity tariff at planning stage. An excellent approach for an in-concrete system in areas having frequent daily use, is to have it connected to a night-rate off peak tariff and limit the hours to the last few hours before the tariff time ends in the early morning. (Usually about 7.00 am) This provides a peak floor temperature at the time it is most appreciated. With an insulated home an nom excessive glass areas, there is unlikely to be any further need for heating until late evening. Various forms of auxiliary heat could then be used if necessary, such as a gas fireplace or reverse cycle air conditioner. The end result of such a combination is a running running cost of around $0.60 per sq.m.per week and the avoidance of cold floors together with the other benefits of floor heating.

An alternative approach, especially for zones having less frequent use, is to select a faster-acting method on the normal day-rate tariff. This could be the thin bed under tile system, or our undercarpet system that is installed over the underlay. The percentage of time that the thermostat cycles the heating on during run times will vary with selected temperature, and the thermal characteristics of the room (insulation, glass area etc). But working on 70% ON, the average hourly cost will be around $0.90 per sq.m.per week if the zone is in use for 6 hours per day.


Floor heating installation cost


The main factors affecting your installation cost, are the floor area, the type of system and the size of individual zones. The only way to obtain a firm and obligation-free price, is to send a copy of your floor plan, usually by email, to our office.

Our installation price does not cover the circuit cabling and connection of the floor heating. Where large installations are contemplated, the capacity of the electricity mains may also become a significant additional factor. The site location and the number of site visits required will also effect the price.

The purchase and installation of DIY kits provides an alternative, especially for small areas.