C, is the Berlin based practice of architect Jens Casper. It covers architectural research, design, and teaching. A 1998 graduate of RWTH Aachen University, Jens has been seeking and developing new collaborations ever since he began an independent practice. Often carried out in the resulting partnerships and co-operations, his work has been internationally recognised, published, and awarded numerous times. He co-founded and established acclaimed architecture offices like Realarchitektur (Berlin) and Casper Mueller Kneer (London and Berlin), and has been contact architect to Berlin for international architecture firms like Inside Outside / Petra Blaisse (NL) and SADAR+VUGA (SLO). 

Jens specialises in the transformation of buildings and the built environment. Particularly outstanding from his built work are Boros Collection Residence and Radialsystem III in Berlin,  White Cube Bermondsey in London, and Phoenixhalle in Dortmund.

Since 2004, Jens held multiple teaching positions. He was Assistant Professor at TU Berlin, and a Unit Master at the AA Berlin Laboratory of the Architectural Association. As a guest professor at BTU Cottbus, he headed the chair "Bauen im Bestand / Contextual Design", as well as a postgraduate Architectural Design Programme carried out by 10 universities across Europe and Israel, incl. BTU. Most recently he has been teaching at the intersection of architectural design and heritage preservation, co-developing The Garage Manifesto and Studio Bagan (Myanmar) as an adjunct professor.

Jens is a board member of Haus Döschnitz eV, a member of the Association of Critical Heritage Studies, of the Chamber of Architects of Berlin, and Bund Deutscher Architektinnen und Architekten BDA Berlin. In 2010 he was appointed into the Konvent der Baukultur der Bundesstiftung Baukultur. He lives and works in Berlin, Germany, and summarizes his practice as C, since 2021.