The circular process begins with the excavation. The nutrient-rich soil was reused for the rooftop garden and integrated into the surroundings of the house, instead of being deposited in a landfill. A variety of earth structures and plants promote biodiversity in the newly created landscape. The KREIS-Haus is built on a screw foundation without any use of concrete. This significantly reduces the impact on the soil compared to a conventional substructure, and the house can easily be deconstructed without causing any long-term damage. Additionally, the base of the building is covered with recycled gravel.

The KREIS-Haus consists of a residential unit made from solid wood, a small living space, and an adjacent conservatory. All the materials that were used in the construction are recyclable, ecological, and free of toxic substances. In addition to natural materials, such as clay and wood, the other building materials are also durable, recycled and reused, for example second-hand windows or recycled glass shards for the flooring. For the kitchen, we used a durable steel, and the furnishing also follows the ecological concept of the KREIS-Haus. 

The semi-transparent solar panels that are integrated into the conservatory (south facing) and the frameless roof-integrated solar system (north facing) produce the required energy for the KREIS-Haus. Second-Life batteries, which were previously used in vehicles belonging to the postal service, store the excess solar energy for later use. The ventilation, heating and warm water treatment also function as a circular system. Warm air from the greenhouse is supplied to the living space by means of a heat exchanger and the ventilation system. In turn, the warm water is heated via a heat pump that uses the warm air exhaust given off by the living space.

The dry toilet operates with a conveyor belt. The toilet saves water and allows for nutrient recovery from the feces. These are processed and used as fertilizer for the rooftop garden. On the facade in the winter garden herbs are grown in a bamboo hydroponic directly in the water. Here, the slightly polluted wastewater from the kitchen and bathroom in the building is cleaned and used for irrigation.