Felix Kayser (1892–1980), as an architect and designer, not only had a significant impact on the Goetheanum building and it's driving principles, but also expanded it in terms of interior design and set a design impulse with the characteristic furniture he had developed, "Kayser furniture," which was organic, anthroposophical, and deeply connected to the spaces it inhabited.
Though he studied architecture at the technical universities in Berlin, Munich, and Dresden, he also painted in an art school and attended drawing courses. During the war effort in Flanders he began, aroun 1918, as an employee at an architectural firm in Nürtingen and devoted himself more fully to landscape painting with a mind to "to make [himself] able to tackle big tasks by working in painting and sculpture in order to achieve the highest in the interaction of architecture, sculpture and painting."
In 1919, Kayser got to know the tripartite movement in Nürtingen through a lecture by mathematician and natural scientist Friedrich Waaser. He then went to Stuttgart, where he heard Rudolf Steiner himself for the first time and became a member in 1920. He joined the Free Anthroposophical Society in 1924, but only after Steiner's death was he able to travel to Dornach. He founded his own office in Stuttgart in 1927 and later that year, following lengthy due process, built the first Goethean building in Stuttgart: a house for Ernst Lehrs.
In addition to building, he dealt with interiors, designing the workshops and bookrooms at Charlottenplatz in Stuttgart and in Jena. With his richly illustrated volume "Architectural Design", which was published in Stuttgart in 1933, he gave for the first time an overview of the buildings and interiors of anthroposophically-oriented architects and designers. The book, the preface of which was written by the city architect Wolfgang Gessner from Kassel, became standard reading for decades to come and made the new building impetus well known. In 1947/48, Kayser founded the "Stuttgart Architects' Circle" together with Gessner and Durach from a smaller working group that had already been established in autumn 1945. With the active help of his second wife Hede Kayser, the organization came to include of regular annual Pentecost meetings and exhibitions for visual artists. The first meeting of artists on May 28, 1947 was attended by around 90 painters, sculptors, architects, and craftsmen. With Gessner and Durach, Kayser also launched the magazine "Mensch und Baukunst" (People and Architecture", which appeared in 1974 and remained unique in this field for its running duration. Building on his experience in housing construction, Felix Kayser was to be the first architect to set up a Waldorf school based on Goethean organic principles: the Free Waldorf School Rendsburg in 1948/50.
A fundamental concern for Kayser was the insight that "without true art, the intellectualization of humanity advances faster and its moral powers decrease more and more." Felix Kayser was guided by an uncompromising artistic objectivity, an almost mathematically moderate art and practicality consistently unifying teacher of new architecture. His numerous contributions to the artistic training of the architect and to the sense show his pedagogical skills.