Because of their extremely tiny damage to the environment and their very tiny primary energy requirement, normally under about ca. 15 kWh/m²a, Bio-Solar-Houses are subsidized among others as CFC 40 Houses by the state. Consumer reports from Bio-Solar-single family houses have shown that:
For providing hot water, room heating and for the romance of an open stove a Bio-Solar-House can manage per year with 3 to 5 cubic meters of logs and about 200 kWh of electricity for pumping the hot water.
With log prices of 80 €/cubic meters wood and 0.20 €/kWh electricity for heating energy costs, this adds up to between 280 € and 440 € per year.
These consumer values change naturally according to the number of occupants, the size of the house, the location, user behaviour and often also with the number of pets.