From 1925 through 1930, Kramer worked for architect and civic planner Ernst May building and furnishing the housing projects of New Frankfurt, and was a contributor to the second CIAM conference. After disputes with the Nazi regime and professional disqualification, Kramer emigrated to the United States in 1938 and worked on a variety of projects, including work with Norman bel Geddes on designs for the New York World's Fair of 1939, designs for inexpensive "knock-down" furniture which anticipate today's commercial "flat-pack" furniture, and commissions from his friend Theodor Adorno for the Institute for Social Research during its New York years. Kramer became a naturalized US citizen in 1945.