Warm and beautifully economical

A cost comparison of heating systems



Which heating system is the best? All homeowners ask this question at some time and their requirements are high. It should provide low heating costs when in operation, and the purchase price should not place a burden on the budget. However, as well as the financial aspects, sustainability and the environment
also play a role. Alternative energy sources such as geothermal, air or sun are associated with higher investment costs, but have the advantage that monthly consumption costs are lower. We suggest that, as the energy consumption of our houses is already low, a system based on a gas condensing boiler represents a good combination of low purchase price and moderate consumption costs. Over the life of the system, a gas condensing boiler in combination with controlled ventilation and a solar energy system offers outstanding value for money.


The Institut für Energiewirtschaft und Rationelle Energie-anwendung (Institute for Energy Economics and the Rational Use of Energy - IER) of the University of Stuttgart compared various heating system types and calculated the annual cost of supplying an average house with heating and hot water, based on a new-build low-energy house with a usable floor area of 150 m² and a heating requirement of 45 kilowatt hours per square metre per annum (kWh/m²a). The heating requirement for hot water is 12.5 kWh/m²a, which corresponds to a KfW Efficiency House 70. Over a 20 year period, operating, consumption and investment costs are compared with one another.

The result:
Although the consumption costs of a condensing gas boiler-based system are higher than those of the other systems, viewed over its useful life it is comparatively the cheapest heating system overall, and efficient in well-insulated houses.





Single family house, 150 m² usable floor area
Central heating requirement: 45 kWh/m²a
Hot water heating requirement: 12.5 kWh/m²a





Electricity: 28.4 cents/kWh          Electricity at heat pump tariff: 20.7 cents/kWh
Natural gas: 8.0 cents/kWh          Pellets: 5.3 cents/kWh



Includes maintenance, repair, servicing, flue cleaning if needed, auxiliary energy for operating the system



Acquisition cost of the complete heating system, divided by
20 years of system service life. The acquisition cost is on the basis of financing of the system at an effective interest rate of 2.12 % from the KfW “Energy-Efficient Building” programme.

Source: The Institut für Energiewirtschaft und Rationelle Energieanwendung (Institute for Energy Economics and the Rational Use of Energy - IER) of the University of Stuttgart. Further details of the calculations can be found (in German) at www.ier.uni-stuttgart.de/linksdaten/heizkostenvergleich
As at: September 2013