Jean Krämer studied between 1903 and 1905 in Mainz and changed to Düsseldorf in 1906. He studied with prof. Behrens. In Behren's office in Berlin Krämer started to work as an architect.
He was first influenced by expressionism and turned in the 1920s to use more ideas of modernism. He designed mostly industrial buildings, but also houses and villas. He is known as the chief architect of Berlin tramways.
He was the architect of Germany's first traffic light, designed as a tower for controlling the traffic at Potsdamer Platz in Berlin.