Between 1925 and 1934 Ruegenberg worked in the office of Mies van der Rohe. It was there where he also designed and sketched the «Barcelona-Chair» for the German pavilion of the World Exhibition, whose construction was assigned to him. He was
significantly involved in the projects of the Villa Tugendhat in Brno, for which he designed the chair and the interior, as well as the 'Neue Wache' in Berlin.
After World War II his artistic career led him to Hans Scharoun. Ruegenberg
preferred the architecture of the «sensual, dynamic Scharoun» in comparison to the work of the «crystal clear, intellectual Mies». In Ruegenberg's mind the conceptional process was identical to a sculptural task, by creating i
nhabitable constructional sculptures, tailoring them for needs of humans.
End of the 1980s, a close cooperation between Sergius Ruegenberg and Axel Bruchhäuser resulted in sketches and drafts for TECTA and a cantilever chair called «
Tugendhafter Sessel» - tugendhaft implying the chair's antecessors, directly meaning virtuous. «The secret is the suspension» Ruegenberg wrote. Finally in 2006, as a result of this coopeartion, the 'tugendhaft' Ruegenberg-Cha
ir was realized.