Janne Kammer-Kret (1906-1984) initially chose to study chemistry after the Rotterdam HBS. When after eighteen months it appeared that a group of six female students had meanwhile been admitted to the study of architecture at TH Delft, she made the switch to this study. She graduated in 1931. A year later she married her fellow student, Harry Kammer (1902-1988). Together they started an architectural firm at home in Schiebroek. In 1960 they settled with their firm in Berkenwoude. Both Janne and Harry Kammer were supporters of the Nieuwe Bouwen movement and joined architects' association Opbouw. Janne Kammer found her graduation project at Granpré Molière (a stone town hall) "very traditional" and she missed the attention and openness to new ideas at Bouwkunde. In 1933 she entered a competition for a "village church with parsonage in a Groningen setting. Under the motto "Tranquility," she chose practical floor plans and sober architecture, which, according to the jury, "nevertheless had a distinguished character. Her first real commission of her own was a vacation home for a family in Oostvoorne. Later designs also reflected her preference for light, air and space and for functional and practical. Examples include her own houses, which she designed together with her husband in 1937 and in 1960, and the Montessori school in Schiebroek (1936). The Rotterdamsch Nieuwsblad wrote of the latter design that it was spacious and light, inexpensive and built with 10,000 pounds of steel that was nowhere to be seen. After World War II, Janne Kammer-Kret's role changed. From colleague and architect with her own assignments, she became more the consultant, discussing the firm's design sketches at the family table in the evenings. She herself made a connection to the postwar growth of the firm due to the increasing number of commissions. In Margaret Staal-Kropholler's (1891-1966) 1951 survey of the work of female structural engineers, she wrote, it was about compromise and freeing up time, but it was difficult with a family of four children.