(b The Hague, 1 Feb 1887; d The Hague, 1962). Dutch architect. He studied (1905–11) at the University of Technology, Delft, and then (1911–12) at the Ecole des Beaux-Arts, Paris. In 1912–16 he was employed by H. P. Berlage and Jan Stuyt before becoming an independent architect in 1916. His early influences reflected a remarkable dualism, his preference for the academic axial symmetrical composition, which he learnt in Paris, being allied to a great interest in technical construction issues, an aspect of his work for Berlage. His mature work, however, is characterized by its flexibility of approach. His many utilitarian buildings, with their severe, unornamented design and use of modern materials, with much concrete, are consistent with the development towards a functionalist architecture. The influence of Frank Lloyd Wright is apparent around 1920, after which Roosenburg’s designs became increasingly severe, for example in the factory building for Philips (1920–29), Eindhoven, executed entirely in concrete with flat façades and large areas of glass, and the office block for the National Mines (1926), Heerlen. The latter, with its severe and open architecture of steel and glass with aluminium-faced façades, is one of the first monuments of the ‘New Building’ in the Netherlands. Roosenburg chose a much more traditional approach, however, for houses and prestige projects, for example the Villa ‘Windekind’ (1928), The Hague, or his competition design (1927) for the Palace of the League of Nations, which was monumental and classical in form and composition. In his most important work, the Rijksverzekeringsbank (1937–9), Amsterdam, he combined the traditionalist and functionalist poles in a perfect synthesis: a modern steel structure with severe unornamented façades, but with a covering of stone and an overall conception of the building as a monumental symmetrical entity. Later works include the KLM Building (1940–47; with Verhave and Luyt), The Hague.