Heidelberg has always been known as a historical and cultural city in Germany as well as the living and working place for many scientists and thinkers, who made prominent contributions to mankind. The city today is once again drawing the attention of the world with its pioneering role as a developing sustainable city. Bahnstadt, a city district that applies the passive house principles in Heidelberg, is currently one of the largest Near Zero-energy residential district planning projects in the whole world.
Bahnstadt is close to the central railway station of Heidelberg and covers an area of 116 hectares, most of which were reconstructed from the former freight train station. According to the plan, the new community will be able to offer a living space for more than 5,000 people as well as a working space for more than 7,000. It fulfills functional requirements such as living, studying, business and recreation. Together with its convenient location and connections to the public transportation, this community has developed into one of the most dynamic new city areas. Meanwhile, the idea of sustainable development has been at all times translated and presented in the continuous planning and construction process. The long-term target is to cover all of the energy demand with renewable clean resources within the Bahnstadt and qualify it to be one of the largest zero-carbon areas in the world.
In the center of this sustainable ecological city area the project “Heidelberg Village” is under construction, which is invested, planned and built by the Frey Architekten Group, Germany. In this project not only different sorts of sustainable concepts are translated into reality, but also new operation and management models are applied, in order to achieve the sustainable development of the environment and society as a whole. With this project, the Frey Architekten received “the initiative ‘Germany – country of longevity’ award (Preis der Initiative ‘Deutschland – Land des Langen Lebens’) in 2015.
Architecture & Design
The Heidelberg Village is located at the intersection of two main landscape axes, in the north of which are tram tracks and in the west a square. The building consists of an eastern and a western part. Its main body has an average height of five stocks and the western end, which is close to the square, is as high as eight stocks. Each part of it is a semi-enclosed bock, which defines a half-open internal public space. The overall gross floor area is approximately 25,000 square meters.
The “Heidelberg Village” distinguishes itself from other passive house projects by an integrated planning with photovoltaic panels on the façade and vertical greening. The photovoltaic panels, installed between the fenestrations on the southeastern and southwestern façade of the building, not only generate renewable energy for the building but also lower the indoor temperature in summer by acting as a sunshade. Besides, installations of a grid structure around the balcony of each dwelling unit offer a proper living condition for climbing plants, which leads to the formation of a “vertical garden”. In this way, residents are provided with a refreshing outdoor space as well as a pleasant indoor space with agreeable temperature. The combination of two ecological building technologies can therefore be visualized and directly experienced, which endorses the uniqueness of the project among others in the Bahnstadt.
The design of roof garden is a further application of the construction ideas above, which values also a combination of the installations of photovoltaic panels and green plants. With certain patterns the photovoltaic panels divide the rooftop into many smaller areas and “lanes” among them. Each square further presents a mixed texture consisting of greenness and hardness, which offers it a special quality. On the green roof are not only grass planted, but also trees. Such a design transforms a normal roof garden into a “roof park”, where people can relax and enjoy at the same time the view from above. This function adds values to the greening, especially in a city, where the greening is normally considered on a plane instead of in a space.
Living Community
In the “Heidelberg Village”, the concept of “Living Community” is practiced. It means a unification of living and life, which goes back to the original meaning of the English word “living”.
The “Heidelberg Village” includes commercial properties on the ground floor and 162 living properties above. Different house types ranges from bachelors apartments and five-bedrooms with different sizes and all of them are barrier-free, which corresponds to a diversified social structure. The artificial landscape in the courtyard and the roof garden offer residents places and occasions where they can comfortably communicate with each other or simply relax. On the ground floor are living service facilities, such as cafeteria and bakery. Under such conditions a close relation with neighbors and a convenient city life can be possible and all together an atmosphere of “being at home” will be achieved in the “Heidelberg Village”.
To better manage the multifarious “living community”, the Frey Architekten Group draws its previous experiences in property management under the “pro-scholare-Model” and founded the “Non-Profit Housing Association of Heidelberg” particularly for the “Heidelberg Village”. Therefore the living community can also be understood as an upgrade of “pro-scholare-Model”. By operating projects and the management of the peripheral communities, the Association creates conditions for services such as nursery, caring and maintenance to the whole Bahnstadt. For example, there are one housekeeping company, one nursery and two home care centers in the “Heidelberg Village”, which provide their services to clients around the city area. A professionalized and diversified service system in the neighborhood can be of great importance for all the families, the aged and those in need in the Bahnstadt.
Energy Concept
According to the evaluation by PHPP, the “Heidelberg Village” has qualified itself for the passive house standard. The ventilation system of it, like any other living building projects by the Frey Architekten Group, is decentralized. The heating model is consistent with that of any other building in the Bahnstadt and adopts district heating, which is generated by renewable resources such as geothermal energy and biomass, to lower the energy consumption.
The electricity supply for the whole Bahnstadt is covered by thermal power stations in the city Heidelberg and the whole process is carbon neutralized. Besides, intelligent electric-meters are installed in all buildings in order to track the electricity consumption at all times. As for the lighting, only LED energy-saving lamps will be used as road lamps and the lighting system as a whole is under the monitor of a remote management system, which can adjust the brightness according to the practical needs.