History Willem Van Tijen, one of the most important pioneers of public housing construction in the Netherlands, initially starts an agency in the 1940s together with Hugh Maaskant that grows into one of the leading housing agencies in the Netherlands. Among other things, they design the Groothandelsgebouw in Rotterdam. Immediately after its inauguration in 1953, the firm settled in this building and is housed there to this day. In 1975 the Werkgroep Kokon is founded as a continuation of the then office Van Tijen, Boom, Posno and van Randen. Due to the increased scope of urban planning work within the firm, the name was changed to Kokon Architecture & Urbanism in 2005.