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Pascal Hentschel has been working for partner company baubüro in situ since 2014 and is also a co-founder of Zirkular. Since 2023 he is part of the management board and coordinates the areas of specialist planning and component hunting. His experience in building with reused materials goes back to his time in the Netherlands where he worked at Superuse Studios in 2008. Since then, he has acquired a wealth of knowledge as an architect in the implementation of reuse projects and in 2020, together with Marc Angst, realized the multi-award-winning pioneering project Halle 118 in Winterthur.

Kerstin Müller is an architect and managing director at Zirkular. Previously, she was a member of the management board of baubüro in situ, Basel. From 2022-2025 she held a guest professorship at the KIT Faculty of Architecture in Karlsruhe. In 2023, she co-developed the Swiss CAS Circular Building and has co-led it ever since. Since 2024, she has headed the “Circular Building Qualification Program” at the AKBW in Germany. Müller is also a member of the design advisory board of the city of Friedrichshafen.

Andreas Oefner is on the management board of Zirkular. He is responsible for the personnel, administrative and financial aspects of the company. After completing an apprenticeship as an architectural draftsperson, Andreas has worked for baubüro in situ since 2006 with some intermittent pauses. In parallel, he studied history in Basel and Bern and received his doctorate in the fall of 2020.

Mario did his carpentry apprenticeship at Schreinermacher where he was able to work at a variety of different companies during his education: two years he spent at Fenster Fabrik Albisrieden (FFA) and two years at Schreinerei Ullrich GmbH. After completing his education, he spent two years as a furniture maker and fitter before beginning work as a structural draftsman in the small architectural office PSA-Architektur AG. There he gained experience and trained internally in various areas including cost control, invoicing and work contracts, and accounting. After six years in the architectural office, he moved to Zirkular in September of 2024.  At Zirkular, Mario brings his experience and know-how of two worlds – construction and planning-execution – to his job of component hunter.

Jasmin studied architecture at the Karlsruhe Institute of Technology (KIT). During her studies, she focused on the area of sustainable construction with a focus on the reuse of building components. An internship at baubüro in situ gave her the opportunity to put what she had learned into practice. Since summer 2021, she has been working as a component hunter and reuse expert at Zirkular. In 2022/23, she supported the visiting professorship of Kerstin Müller and Oliver Seidel at the KIT Faculty of Architecture on the topic of “Sustainable Materials for a new Architectural Practice – Entering a Circular Economy” as a research assistant.

Pascal graduated from the ZHdK as an industrial designer in 2010. Since 2017 he has been a member of the management team and board of directors of our sister firm, baubüro in situ. In this roll, he acts as a bridge between the offices, supporting reuse projects and making the best use of the synergies between the firms and their teams.

After an apprenticeship as a draftsperson and several years of work experience in Vevey and Bordeaux, Marc began his studies as a spatial planner with a focus on urban planning at the HSR in Rapperswil. At baubüro in situ he has been working for years as a project manager for circular and sustainable construction practices. In this context, he realized the pilot project Kopfbau Halle 118 in Winterthur as a project manager together with Pascal Hentschel, decisively advancing reuse in Switzerland. As co-founder of Zirkular, Marc is strongly involved in the development and research of reuse processes in construction.

Charlotte studied civil engineering at the University of Stuttgart. She has been working at Zirkular since May 2021 where her knowledge from her master’s degree with a focus on modeling and simulation, her work as a structural engineer, and her numerous continuing education courses and self-study on regenerative construction all flow into one another.
Together with Basil Rudolf, she is responsible for the area of building science at Zirkular, tackling questions and processes concerning the reuse of load-bearing components as well as for the life cycle assessment of reuse projects.
Privately, she is also committed to a feminist building revolution: During intensive periods with the Rethink Materials Kollektiv and Architects for Future Germany, most recently in the context of the exhibition Queens of Structure.

Barbara is a qualified architect (ETH) with an additional certification in the topic of building energy studies. Among many other projects, she founded the Bauteilbörse Basel association and the Bauteilnetz Schweiz parent organization in 1995 as well as our sister firm baubüro in situ in 1998. Through her extensive work and leadership, Barbara has been shaping reuse in the construction industry for 30 years. Without her, Zirkular would not exist. Barbara continues to be actively involved in the team as an expert in circular construction.

Blanca Gardelegui is an architect, researcher, and consultant specializing in sustainable building and circular architecture. Since 2022, she has worked as a ReUse expert at Zirkular, advising pilot projects focused on material-efficient design and CO₂ reduction. From 2017 to 2024, she held various academic positions at institutions such as ETH Zurich, KIT, INDA, and the AA Visiting School. In 2024, she was a visiting professor at EPFL Lausanne alongside Ariane Widmer. Previously, she worked at international firms including Herzog & de Meuron and KOSMOS Architects.

Laia has been studying architecture at ETH Zurich since 2017. During her bachelor’s degree, she completed various internships in which she gained construction site experience. She is currently completing her master’s degree, in which she is also involved in the working group for sustainability at the Department of Architecture at ETH Zurich. Laia joined Zirkular in February 2021 via a one-year internship as a component hunter. Since her personal interests revolve primarily around the intersections between architecture, the environment, the climate crisis, and activism, working at Zirkular was an obvious choice. The position turned out to be such a good fit that Laia switched to a permanent position after her internship. At Zirkular, in addition to component hunting, she is involved in the development of a digital tool for circular building and organizes deconstruction workshops for students and interested architecture professionals.

Nora studied structural engineering at ETH Zurich. During her studies, she gained early practical experience in engineering with an internship in urban planning in France and with a part-time job in an engineering office in Switzerland. Her passion for sustainable construction grew during her Master’s degree and led her to focus on this specialization after graduating in the summer of 2022. She has been working at Zirkular since August 2024. There she utilizes her knowledge in the areas of building screening and technical expertise.

Christoph is a co-founder of Zirkular and advises real estate developers and architects. His focus is on strategies for the preservation of buildings and planning support for the reuse of building components. He received his architectural education from the Vienna University of Technology. Before joining Zirkular, he worked as a project manager at baubüro in situ with a focus on “Simple Housing” for refugees. Earlier in his career, he also worked at the United Nations and international NGOs in the field of “humanitarian shelter”.

Anna studied architecture at the RWTH in Aachen. During her studies, she focused more and more on building in existing contexts and the reuse of building materials. In 2021/22, she worked for a Norwegian digital reuse platform as a circular building advisor and gained her first practical experience in the field of reuse in Germany. She is also involved in volunteering for a change in the construction industry. Since 2023, she has worked as a reuse expert and project manager at Zirkular in Basel.

Selma has been studying architecture at the Bauhaus University Weimar since 2020. During her bachelor’s degree, she first worked as a student trainee at DETAIL magazine and then began a six-month internship at Zirkular. Since August 2023 she has been permanently employed at Zirkular as a component hunter.

Franziska studied architecture in Karlsruhe. She worked as an architect and architectural journalist in Berlin and Zurich. Since 2022 she is responsible for the coordination of public relations at Zirkular.

Basil made his debut in the construction industry with his apprenticeship as a metalworker. After his years as a craftsman, he remained loyal to metal, but switched from the trades to the office when he began studying engineering. Pursuing specialized study and work at both the university and in the private sector, he acquired diverse knowledge in the development, testing and certification of window and glazing systems. In search of sustainable construction methods, material diversity and instruments for ecological evaluation, he then landed in the field of building physics. Wanting to use his training and experiences for an effective sustainable impact, Basil joined Zirkular in 2021. He now oversees the area of technical building physics together with Charlotte Bofinger.

Chris gained experience on the construction site as a team leader and specialist for civil and geotechnical engineering in Switzerland, but also in Asia and the Middle East. In 2017, he joined baubüro in situ as a construction manager. With his versatile experience, he contributed significantly to the realization of complex projects such as the site development Lysbüchel in Basel North, the conversion of the ELYS Kultur- und Gewerbehaus and the reconstruction of the Klinikhotel Schützen in Rheinfelden. Due to his special interest in process management, controlling and digitalization, he focused on deepening his expertise in these areas. In 2022, he moved to Zirkular to further expand the acquired competencies in digitalization and project management in the field of construction with reused materials.

After completing her training as an architectural draftsperson, Julia pursued a bachelor’s degree in Fiction Illustration at the Lucerne University of Applied Sciences and Arts and graduated in the summer of 2020. She has been working at Zirkular since December 2021 and is responsible for visual communications.

In 2019, Alexander successfully completed his bachelor’s degree in architecture at Leibniz University in Hannover. Seeking practical experience in construction, he then opted for training as a carpenter. His membership at Architects 4 Future brought his attention to the opportunities of reuse for more sustainability in construction. Since 2023, he has been employed at Zirkular in Zurich, where he is actively involved in developing the discipline of building screening, inventory and component hunting as a field unto itself within the practice of reuse.

Laura completed her studies in product design at the School of Design in Zurich in 2024. During an internship with Alfredo Häberli, she deepened her design skills and gained valuable practical experience. In her final thesis, she focused on the topic of circularity and developed a circular design intervention for Zurich City Hall. Since August 2024, Laura has been working as a designer at Zirkular, where she contributes her expertise in visual communication and product design.

Janine studied architecture at ETH Zurich and then gained experience in various Zurich architectural offices. Along the way, she became passionately involved in collectives dealing with topics such as architecture, sustainability and activism. She is a member of the Flinta* Baukollektiv (Flinta* Building collective) and is involved in both practical construction and the organization of workshops. She has been working as a component hunter at Zirkular since 2024.

Hannah  studied architecture and urban planning, first at the University of Stuttgart and later at the TU Delft in the Netherlands. In various academic and professional projects, she has developed a focus on the reuse of building components, design for disassembly and sustainable building design. As a member of Team SUM, she was responsible for the implementation of sustainability strategies at  every scale of their Solar Decathlon Europe 2022 project submission.  The project centred on the preservation of existing building fabric and the use of reusable or recycled materials. With this interest, she applied to Zirkular, where Hannah has been working as a component hunter since summer 2024.