The new replacement building of the hotel, located right next to the town hall, offers 72 rooms, two suites, as well as spa, restaurant and underground parking facilities to guests from all around the world. Quality and guest comfort levels were the highest priority – realized through a simple, sleak and cost-effective concept which combines sustainable construction with low use of locally sourced energy. In coordinatiion with the design team, Transsolar developed the concept for energy, climate, and ventilation. Thermal comfort and daylight supply are guaranteed, and energy use is as low as possible, both developed via detailed simulations. Decentralized bathroom exhaust fans povide basic ventilation, drawing in fresh air via a passive downstream element in the facade. Moreover, guests may open windows for addtional ventialion. Ventilation through the windows combined with the thermal storage capacity of the exposed concrete ceilings allows for passive cooling of the hotel rooms during the transitional seasons. An external, movable sunshade regulates solar heat input and prevents overheating of the rooms. During the summer, a Gravivent System actively cools the rooms without a fan and almost silently according to the principles of gravity: warm air rises; at the top of the room it enters the system through a grid and cools down at the heat exchangers. The now cooler, heavier air falls down through a shaft and returns to the ground through air outlets in the room. Heating is provided by individually controllable convectors in the facade. They pre-heat the incoming outside air and heat the room together with the Gravivent System as this is also connected to the heating network. Utilizing the Gravivent System is unique for hotels in Germany. The energy system of the building is designed for low temperatures (95/82.4 °F) for efficient heat generation. It uses a bivalent-operated brine-to-water heat pump, which is coupled to the probes of a geothermal system. The peak heating load and domestic hot water preparation are provided by a CHP and a gas peak boiler of the neighboring town hall.