Known for rising, rectangular structures that influenced modernist architecture. He sought to make the buildings of his day as distinct and unique to their era as Classical and Gothic designs. "Less is more" and "God is in the details" were two of his favorite quotes.
He was construction manager of the Embassy of the German Empire in Saint Petersburg under Peter Behrens. He developed a style that was simple in design, where elegant form was always backed up by versatile function.
His most notable designs included the Seagram Building in New York City, the Museum of Fine Arts in Houston, and the new National Gallery in Berlin.
He had three daughters with his wife, Adele Auguste Bruhn, and also carried on a high-profile relationship with German designer Lilly Reich.
He and Frank Lloyd Wright were considered pioneering influences on modernist architects.