The Karlsruhe Institute of Technology participated in the 2021/22 Solar Decathlon Competition in Wuppertal, Germany with its project RoofKIT. Designed as a top-up to an existing structure of the 19^th century in the old city fabric, it demonstrates a vision for the building industry: social adequate, energy positive and circular sustainable.

Images © Zooey Braun

It is the unique character of the Solar Decathlon competition, that next to an overall design approach of a larger project, a characteristic element is constructed as a full scale demonstrator. Since 2020, more than 100 students from KIT within different faculties and under the leadership of the professorships of Sustainable Construction (Prof. Dirk E. Hebel) and Building Technologies (Prof. Andreas Wagner) worked on the project which cumulated in the construction of the House Demonstration Unit in May and June 2022 in Wuppertal, Germany.

Images © Zooey Braun

Designed as a prefabricated module system with a 100% circular construction method, the unit proofs already today, that with current technology and design capacities, we are able to fulfill the requirements of the European Green Deal. No glues, no paints, no foams or wet sealants were used, so that the circularity of the building and its materials is guaranteed. In addition, only mono-materials were used for construction, meaning no composites or mixtures of materials are to be seen.

But RoofKIT wants not only show what is possible in the future: many building components and materials are taken already out of the urban mine and are used in their second, third or even fourth circle: wood from old barns in the black forest, the entrance door from a building of the 19^th century , windows from a demolished building in Basel, bathroom and kitchen sinks as well as fixtures from turn backs of fair exhibitions.

Images © Zooey Braun

This circular approach only makes sense when it is powered by renewable energy. As the RoofKIT top-up is a new construction with a high energy efficiency standard, the total energy demand (including appliances and e-mobility) will be covered by solar systems on the building envelope. For solar harvesting PVT collectors are used which simultaneously provide electricity and heat, the latter serving as the source for a heat pump which feeds a floor heating system and hot water tank. The surface of the PV modules is colored with a special coating technology in order to merge with the copper roofing with almost no losses in efficiency.

Image © SDE 2021-22

This important step is necessary to fully integrate solar panels into the design approach of future buildings. The overall light concept follows the idea of avoiding unnecessary fixtures where possible and using flexible hand-carried cable-free elements to illuminate only those areas where wanted. In addition, an artificial lighting system around the core delivers light with a luminous color adapted to the time of the day.

The unit sits on a scaffolding structure to demonstrate its character as a top-up design strategy. RoofKIT already today is a demonstrator for our future building culture and industry.

Images © SDE 2021-22

On Friday 24 June at about 6 pm, the time had finally come – the Competition Director of the Solar Decathlon Europe 2021/22, Kasten Voß, in Wuppertal announced the winning team of the student competition: Team RoofKIT from Karlsruhe! The team was very surprised about this development and expressed their relief, happiness and pride. The moment of the announcement was captured on video by SDE 2021/22:

Video © SDE 2021-22
Cut © Luca Diefenbacher, Elena Boerman

Many people have been working on the project in the last two years. Project credits go to:

Core student team KIT Karlsruhe: Patrick Bundschuh, Stefanie Christl, Luca Diefenbacher, Florian D’Ornano, Jonas Ernst, Dominic Faltien, Nadine Georgi, Aaron Harter, Johannes Hasselmann, Louis Hertenstein, Michael Hosch, Martin Kautzsch, Jennifer Keßler, Nicolas Klemm, Katharina Knoop, Sebastian Kreiter, Anne Lienhard, Michelle Montnacher, Fabian Moser, Friederike Motzkus, Jana Naeve, Saskia Nehr, Julian Raupp, Alexander Resch, Nicolas Salbach, Julian Schmidgruber, Natascha Steiner, Niels Striby, Dennis Sugg, Moritz Tanner, Sven Teichmann, Benjamin Weber, Vincent Witt, Immanuel Zeh

Project Leader: Regina Gebauer (Architecture) and Nicolás Carbonare (Building Technology)

Architectural Design: Faculty of Architecture, KIT Karlsruhe, Professorship of Sustainable Construction, Prof. Dirk E. Hebel, Regina Gebauer, Sandra Böhm, Katharina Blümke, Elena Boerman, Hanna Hoss, Philipp Jager, Daniel Lenz, Manuel Rausch, Daniela Schneider, Alireza Javadian, Nazain Saeidi, Elke Siedentopp with Michael Hosch, Benjamin Weber, Martin Kautzsch, Julian Raupp

Building Technology: Faculty of Architecture, KIT Karlsruhe, Professorship of Building Technologies, Prof. Andreas Wagner, Nicolás Carbonare, Isabel Mino Rodriguez with Martin Kautzsch (cooperative partners: Klaus Rohlffs, ip5 Karlsruhe; Prof. Jens Pfafferott, University of Applied Sciences, Offenburg; Martin Wortmann-Vierthaler, Heinrich-Meidinger-Berufsschule, Karlsruhe, David Wölfle, FZI Forschungszentrum Informatik)

Structural Design demonstration unit: 2hs Architekten und Ingenieur, Prof. Karsten Schlesier HCU Hamburg with Johannes Hasselmann and Jonas Benjamin Ernst

Structural Design circulation, foundation and safety elements: Faculty of Architecture, KIT Karlsruhe, Professorship of Structural Design, Prof. Riccardo La Magna, David Andersson

Structural Design scaffolding system: DOKA, Alexandra Sell und Markus Wientzek

Light Design: Faculty of Architecture, KIT Karlsruhe, Professorship of Building Technologies, Prof. Andreas Wagner, Luciana Alanis with Erik Hofmann and Maikel Hollstein

Urban Mobility: Faculty of Architecture, KIT Karlsruhe, Professorship of Urban Design, Prof. Markus Neppl, Peter Zeile with Nicolas Salbach and Daniel Lenz

Feasibility & Affordability, Life cycle Assessment: Faculty of Economics and Management, KIT Karlsruhe, Professorship of Sustainable Management of Housing and Real Estate, Prof. Thomas Lützkendorf, Daniel Rochlitzer with Regina Gebauer and Julian Schmidgruber

Material Library: Elena Boermann und Sandra Böhm mit Anna-Lena Kneip

Corporate Design and Communication: Philip Brücher, Nadine Georgi, Dominic Faltien, Lukas Großmann, Jennifer Keßler, Katharina Knoop, Michelle Montnacher, Saskia Nehr, Sanda Sandic, Natascha Steiner, Katharina Blümke, Daniel Lenz, Manuel Rausch

Fabrication demonstration unit: Kaufmann Zimmerei und Tischlerei, Reuthe, Bregenzerwald, Österreich, Matthias Kaufmann, Mario Meusburger with KIT students

Supported by: KIT Karlsruhe, German Ministry for Economic Affairs and Climate Action, Holzbauoffensive Baden-Württemberg, Energy Endeavour Foundation

Sponsoring Partners:

More information about the project on the following websites:

www.roofkit.de
www.sde21.eu
www.nb.ieb.kit.edu

Images below © Zooey Braun