Das Projekt "Passive Nutzung von Solarenergie in einer Gruppe von fuenf Reihenhaeusern" wird vom Umweltbundesamt gefördert und von Domosolar AG durchgeführt. Objective: Demonstration of innovative construction of 5 row houses, opened to the South with protection to the North, heat recovery system for shower and kitchen water and application of air floor heating systems, which should reduce energy consumption compared to a conventional house by 60 per cent. The calculated annual load for space heating is approx. 8400 kWh/year. General Information: The five row houses are opened to the South, protected by plantation to the West and by an earth dam to the North. The houses have a total volume of 510 m3 and a total heated area of approx. 120 m2. The space heating demand is calculated to be 8400 kWh/year against 27500 kWh/year of a conventionally built house. This is achieved by improved insulation, direct solar gain, sun space and a heat recovery from sewage water. The middle house - South is used as an office building with four people. The use of air heating systems in the floor and a heat recovery system from warm sewage water deriving from the kitchen and bathroom is innovative for individual row houses. Solar energy is used by an attached sun space, active solar system for DHW (Domestic Hot Water) and solar air collectors with heat storage system. In order to optimise air heating systems for further applications five different systems will be built: 1. Conventional air heating (system Brink) incorporating a sun space for air-warming up, 2. Like 1, but the sun space is replaced by solar air collectors; 3. Like 2, but with a short term heat storage system, 4. Air warming-up by conventional gas fired heat generator or air collectors and room heating by a special floor heating system ; heat storage system, 5. Like 4, but with a sun space instead of air collectors. Variants 1 to 3 are operated as open systems, the warm air is transported directly into the rooms and then sent back in the warming-up system. Variants 4 and 5 use the combination of an air heating with floor heating system (a so-called air floor heating system). These two variants include also sun boilers for DHW. In the 3 first variants DHW is produced by a gas fired boiler. Achievements: The energy consumption show that the houses at the end of the terrace have a higher energy load than the middle ones, this was expected. The highest consumption is in corner house east in January (= 100 per cent) against the house used as an office (72 per cent).