Madis Laas: Väga hea lähenemine küttekuludele, e. 0.- raha aastas, vt:

http://www.solar-aktivhaus.com/solaraktivhaus/en/sonnenenergienutzung.asp 
The Solar Active House is heated exclusively by the sun—year-round, one hundred percent.
The Solar Active House is the first type of house that receives its entire, year-round energy demand for heat and hot water solely from free solar energy.
This type of house, which was developed in cooperation with the well-known solar architect and engineer Georg W. Reinberg, offers an abundance of key benefits:

• No energy costs for heat and hot water
• Complete independence from fossil fuels
• Unique “Building Biology” (predominantly wood, clay, cellulose)
• Comfortable, healthy indoor environment
• Bright rooms with big windows and open spaces
• No problems with overheating in the summer
• Always a fresh supply of sanitary hot water from a continuous flow water heater