Great success of the coLLab team at the "SOLAR DECATHLON EUROPE 21-22"

For three years, a team of around 250 people from HFT Stuttgart worked together in an interdisciplinary manner and with a clear vision to achieve a goal: a concept for urban, ecological redensification with which we, as a university, are participating in the Solar Decathlon Europe 21/22 in Wuppertal. The development of an innovative concept with great transfer potential and high relevance was one major challenge; the other was the implementation of a demonstration unit derived from it in the form of a fully functional prototype that depicts the overall project and makes it tangible.

Climate-Fair - Resilient - Networked The project to design a highly efficient building that is powered by renewable energies, including the holistic demands of the competition, which are evident in the ten disciplines, is in high congruence with the special profile of the HFT Stuttgart: climate-fair, resilient, networked. This is shown by the outstanding result of our interdisciplinary cooperation across faculty and study program boundaries.

Strong teams and impassability The HFT team is made up of four areas: The core team coLLab consisting of students from different fields of study, a management team consisting of researchers and employees of the administration and workshops, a mentoring team consisting of professors as well as external partners and supporters. Numerous obstacles accompanied the long road to Wuppertal: economic uncertainties, material shortages and the pandemic were particular challenges.

The visions of the coLLab team From three possible given competition scenarios that depicted real urban challenges in the existing building stock, the coLLab team decided on the option of adding a storey. They chose the university building (Building 5), a typical building from the 1950s in concrete skeleton construction on the campus of the HFT Stuttgart, as their existing building, which, exemplary for many such buildings in Europe, was not only to be raised but also renovated at the same time.

The two-story addition, which should be as light as possible, is intended to provide new living space for students, university staff, and low-income user groups, while the lower floors will feature open workspaces, co-working spaces, community workshops, seminar rooms, and a café. The vision is for architecture that fosters community and creates a vibrant neighborhood, a place of exchange and social interaction. Another important motif is life-cycle sustainability. The energy and facade concept take this into account. The facade cladding is made of recycled wood, organic PV (OPV) collectors on the facade and roof are installed to contribute the maximum benefit to indoor comfort. The lower part of the façade is greened and a solar chimney supports natural ventilation. The underlying wood construction of the addition is transferable to other existing buildings at any time by adapting the grid. This was also an essential aspect in the planning and implementation.

The solar decathlon: put to the test in ten disciplines The competition phase started on June 10, 2022. Before that, the first challenge for the coLLab team was to set up the demonstration unit in Wuppertal, which illustrated in excerpts the concept for post-densification that had been developed over such a long period of time. A total of 18 international student teams were at the start. As in the Olympic decathlon, all teams had to compete in ten disciplines. Five of the disciplines were specifically aimed at urban challenges, supplemented by the five core disciplines of the SDE - architecture, communication, comfort, sustainability and energy performance. Both the overall building concept in the Design Challenge and the demonstrators built in Wuppertal on the Solar Campus in the Building Challenge were evaluated. Depending on the contest, this was done either by measurements or by an international jury of experts.

In the course of the competition, a total of seven submissions were made, documenting the progress of the project and the specified tasks. These were included in the overall evaluation. The team that achieved the highest total number of points at the end was the winner in the overall evaluation.

It is no wonder that the coLLab team and all university members were eagerly awaiting the rankings and the awarding of prizes, and each time eagerly awaited the announcement of the individual results. Crossing their fingers was worth it, the coLLab team achieved many valuable awards.

First prize in the discipline "Engineering & Construction" In this discipline, the focus was on the planning and implementation of the technical and building physics concepts. The qualitative architectural integration and the proportionality of the concepts with regard to climate-neutral building operation were evaluated.

Fourth prize in the Communication & Education (CESA) discipline CESA stands for Communication, Education & Social Awareness. In this discipline, the aim was to develop a communication strategy that addresses the project itself, the Solar Decathlon competition and the challenges of the urban energy transition. The aim was to address and involve as diverse a target group as possible through various media and events. A unique selling point of the coLLab team was to use three of the modules of the prototype as an exhibition area to inform visitors about the project and the challenges of our time.

The team also won the "Out of Competition Awards", which focus on outstanding achievements and topic-specific solutions for various future trends. They were awarded by institutions and associations, which thus support the transfer of knowledge between research and application. In the out-of-competition awards, the coLLab team was awarded the following prizes:

Second place in the Timber Construction Award Justification from Informationsdienst Holz: "New forms of housing in combination with offsite production were the team's main focus. The scalability of the design shows a compelling path to the future of light construction and renovation in wood. The architectural expression and structural design harmonize seamlessly and demonstrate the students' interdisciplinary collaboration."

Second place in the Indoor Air Quality Award Justification of the Fachverband Gebäude-Klima e.V.: "The contribution of the coLLab team is characterized by a very courageous ventilation concept with an exhaust air stack that can be used as a preheating supply air shaft in winter. An adiabatic evaporative cooling system is architecturally integrated into the concept via a trickle film application in the downstream area. By means of a well thought-out multi-variable control concept, the operation of the system under different operating conditions could be explained in a comprehensible way. Possible comfort restrictions as well as fire protection issues still need to be clarified in the opinion of the jury."

Third place in the Building for Future Award The reason given by the Solingen-Wuppertal District Trade Union & Düsseldorf Chamber of Crafts: "The Solingen-Wuppertal District Trade Union & Düsseldorf Chamber of Crafts award this place for outstanding craftsmanship. The innovation, ideas, execution details and material selection and combination from a craftsman's perspective were evaluated in the expert audience voting."

Third place in the Applied Mobility Sciences Award The Applied Mobility Sciences Award was presented by the European Platform of Transport Sciences (EPTS Foundation e.V.).

Sustainable Architectural Lighting Award and Human Centered Interior ArchitectureAward Second place in the Sustainable Architectural Lighting Award, presented by the Deutsche Lichttechnische Gesellschaft e.V. (German Lighting Society), and third place in the Human Centered Interior Architecture Award, presented by the Bund Deutscher Innenarchitekten (Association of German Interior Designers). Both prizes were awarded together.

People's Choice Award The most popular house among the public was selected by vote. The coLLab house came in third place.

"coLLab" stands for cooperative and since Wuppertal also for successful collaboration! A great achievement with numerous stages and challenges lies behind all those who have worked hard for the participation of the HFT Stuttgart in the Solar Decathlon 21/22, campaigned for it and finally turned the concept into reality.

It has been a long process, from concept development, as-built analysis, review of the supporting structure, studies on the energy concept, building simulations on lighting, model submissions to the competition organizers, gaining sponsors, developing prototypes in the workshop, developing a communication concept and much more. The coLLab team was only able to bring this to a successful conclusion through tireless commitment, improvisation, the contribution of know-how from many sides, perseverance, willpower and ultimately - in keeping with the name "coLLab" - because: coLLab stands for "collaboration", i.e. cooperative collaboration!

The Stuttgart University of Applied Sciences is very proud of what the coLLab team has achieved and congratulates on behalf of all university members on this great, successful achievement!