 The research and accumulated experience with solar design then spread across the Atlantic by architects like Walter Gropius and Marcel Breuer.Besides from these early examples, the heating of homes with the sun made slow progress until the 1930s, when several different American architects started to explore the potential of solar heating.The pioneering work of these American architects, the influence of the immigrant Europeans, and the memory of the wartime fuel shortages made solar heating very popular during the initial housing boom at the end of World War II.