Although he received little formal architectural training, Breuer began to design buildings in addition to furniture, and by 1928, had opened an office in Berlin. He moved to London in 1935, where he completed several architectural projects, and designed a line of plywood furniture for Isokon. In 1937, he accepted a professorship at the Harvard University School of Design which he held through 1946, when he abandoned teaching for the full-time practice of architecture. His firm won many important commissions, including private houses, the Whitney Museum of American Art, and the UNESCO building in Paris.

Breuer's most notable furniture designs include the Laccio table and chair (1926), the S285 desk (1930), and the whimsical F41 chaise longue, mounted on bicycle wheels (1930).