Austrian architect, whose rejection of all ornament, curves, and decorative features had a profound influence on a generation of architects. He was not, however, himself a successful architect.
Born in Brno, Moravia (now in the Czech Republic), he studied in Dresden and then spent the years 1893–96 in the USA, where he was strongly influenced by Louis Sullivan (1856–1924). On returning to Vienna he spent the rest of his life there, except for six years (1922–28) in Paris. In 1908 he wrote his famous article Ornament and Crime, in which he argued that the use of ornament in architecture was now obsolete and that its presence in modern buildings was degenerate. His Steiner House in Vienna (1910) used the new material, reinforced concrete, in severe curveless cubic forms without decoration of any kind. The result deeply influenced Gropius and through him the Bauhaus movement, with the result that an architectural fashion was set for a whole generation. The severity that led to brutalism owes much of its roots to this single early essay in reinforced concrete. It is perhaps ironic that several of Loos's later buildings make free use of classical decoration.