The simple facts is that there are many factors which determine the impact of how much power is used ie the quality of the room insulation, running time, running temp and whatever you are paying for your electricity.

However as a general rule of thumb, in a modern house built in line with current building regulations and using Thermowarm insulation panels and Thermowarm as the sole heating source, costs are from as little as 0.7pence per mtr2 per hour.

So a 10mtr2 floor run for 5 hours would be:

10mtr2 x 0.7pence x 5 hours= 35pence total.

Thermowarm Electric under floor heating is more efficient than radiators and other heat convection devices. 100% of the energy used is output as heat, this is not the same for other devices.

Also Thermowarm Electric Underfloor heating requires no maintenance and is guaranteed for life, whereas most boiler hot water systems are only guaranteed for 10 years and require maintenance. Also hot water pipes burst!!