After completing the “Pro Scholare” project, the Frey Architekten Group continued to practice the concept of urban sustainability and invested another ecological sustainable residential building “Greenhouse” in the city district Rieselfeld, Freiburg. This building exemplifies a combination of sustainability and ultra low energy consumption principle, achieving an advance from the “Pro Scholare” project from the social, ecological and economical perspectives.
The “Green House” got its name from a three-dimensional greening design for the balconies on the façade along street. Self-supporting hanging balconies with steel structure are enveloped with meticulously designed stainless steel webbing, which provides trellises for climbing plants without hindering the views from the interior. Surrounded by the green plants, the balcony is like pavilion in a garden, creating a comfortable zone for stay in the semi-outdoor space. It can also act as a shelter for the building to reduce the solar radiation and isolate the transportation noise from the outside.
In regards to administration, the Greenhouse employs the “Pro-scholare” models, developed by the Frey Architekten Group. All 86 residential units adopt diversified room layouts. To enhance a harmonious relationship among neighbors, in each storey of the building there is a semi-public “shared living room” facing the courtyard, to which residents can freely apply their own designs and decorations, which on the one hand maximizes the utilization of a transporting space and on the other enforces the uniqueness of each storey and the identity of the residents.
Ecological Construction Techniques
Decentralized ventilation system
The outer wall of the main functional spaces in each residential unit such as the living room and the bedroom is equipped with small-sized ventilation installations that provide a clean air supply with heat recovery efficiency of 90%. Inside of it there is also a fine dust and toxin detector that can control the individual room fans and adjust the ventilation efficiency. Compared to a centralized ventilation system, such a design corresponds to diversified needs with optimum precision and is space saving for it avoids the construction and maintenance of ventilating ducts with large scale.
Photocatalytic façade coating
The Greenhouse not only realizes a precise air control in the interior, but also contributes to the air quality in the surroundings, thanks to the special paint on the façade of the building Sto Photosan NOX. The titanium dioxide contained in the paint acts as a catalyst with the participation of light. In a photosynthesis-like process, nitrogen oxides are converted into oxygen and environment-harmless nitrate ion, which are attached to the façade and can be easily washed out by the rainwater.