Funded by the national climate protection initiative of the Federal Ministry for the Environment, Nature Conservation, Building and Nuclear Safety, Bremen University of Applied Sciences built the FahrradRepairCafé as a meeting place in the center of the new FahrradModellQuartier.
The design and construction of the building reflect the ideas of sustainable building, particularly through the geometry, structure and choice of building materials. The gross floor area of the wooden structure is approximately 140 square meters.
A compact solid wood core with ancillary and technical rooms divides the building into a café and a workshop area for bicycles. Both areas can also be used as an event space. Characteristic structural elements of the building are the funnel-shaped wooden roof made of prefabricated BSP elements and the transparent facade, which ensures a high degree of connection to the outdoor space.
The building stands as an eye-catcher in front of the historic main building of the Bremen University of Applied Sciences and incorporates the historical context into the building design. The multiple constraints of historic preservation and the exposed urban location were carefully balanced with the high demands of an energy-optimized building. The preservation of the trees on the forecourt of the listed main building was mandatory and a maximum of transparency for the new building was desired. These requirements initially conflicted with an energy-optimized building design. A careful analysis of the site, including detailed shadow studies, finally allowed the seemingly conflicting requirements to be successfully combined in the design. In summer, large parts of the new building are shaded by the neighboring buildings and trees. The preserved ornamental apple trees also contribute to the shading of the northwest facade for a pleasant climate in the building.
As the modern glass facade suggests: The School of Architecture has its fingers in the pie here (Prof. Ulrike Mansfeld/Prof. Michaela Hoppe/Prof. Dr. Martin Speth/Prof. Ingo Lütkemeyer). HSB architect Justus Dietz was awarded the "ICONIC AWARD 2020: Innovative Architecture" for the project. The folded roof structure made of prefabricated BSP elements cantilevers without supports far above the compact wooden building core and is supported only by the slender profiles of the steel and glass façade. The upper crossbeams of the steel and glass construction are flush with the sloping BSP ceilings, so that the sloping surfaces are not visually interrupted and continue dynamically into the exterior space. Thus, the slopes of the ceiling surfaces create a sense of expanse in the interior space and, through the minimized roof edges, emphasize the intended transparency and filigree appearance of the structure. The folded BSP construction also allows the use of slimmer material cross-sections, thus saving a considerable amount of material.
The main idea behind the energy supply is that as little CO2 as possible is released for the energy requirements of the FahrradRepairCafé such as heating, cooling, ventilation, hot water use and general electricity. The building is not considered an autonomous unit, but is designed as part of an overall regional energy system. The energy supply has been adapted to the changed limits of the energy transition and takes into account the economic use over the entire life cycle. The energy concept for the FahrradRepairCafé pursued here deliberately does not aim at current building definitions such as zero-energy or plus-energy house. These definitions allow energy or CO2 credit for renewable electricity generated by the building's winter energy demand or CO2 emissions. The bicycle repair café may only be powered by regionally available renewable electricity. An electric air source heat pump is available for sustainable heating and cooling. If excess energy is generated, it is stored in a battery storage system and can be fed back into the system as needed. If no renewable or stored energy is available, the pellet stove connected to the system is activated.
The ZETA - Center for Energy Efficient Technology and Architecture with Prof. Ingo Lütkemeyer and Prof. Dr. Rolf-Peter Strauß was also significantly involved in the planning and construction. Student projects on the FahrradRepairCafé were carried out in the fields of architecture and design (Hochschule für Künste), with Prof. Ulrike Mansfeld and Prof. Rahe (HfK), energy and environmental engineering with Prof. Dr. Jana von Horn and civil engineering with Prof. Dr. Carsten-W. Müller and Prof. Dr. Stephan Lochte-Holtgreven.
In the future, the building can be used as a real laboratory for students to test modern architecture and statics as well as low-CO2 building services in the immediate vicinity of the university.
The entire project was made possible by Dipl.-Ing. Steffi Kollmann, who initiated the bicycle model project and the BicycleRepairCafé, campaigned for the promotion of the bicycle model quarter and has accompanied the project and its implementation for years. The café and model quarter were largely funded by the German Federal Ministry for the Environment as part of the ClimaCampus project under the National Climate Protection Initiative.