Brothers Jan and Wim Oomen establish the architectural firm Gebr. Oomen before 1900. In 1919 brother Anton joins as a partner. From 1932 Bernard Oomen (son of Anton) joins the company. In 1933/34 Anton's second son, Petrus Oomen, also joins the company. Petrus died in 1934. In 1935 father and son Anton and Bernard Oomen establish their own company: architects and engineers Oomen (Kloosterstraat 25, Oosterhout). Brothers Jan and Wim continue with Gebr. Oomen at Heuvel 10 in Oosterhout. Gebr. Oomen existed until 1950.