Date published 20-06-1970. The author, K.L. de Vries, director of the Bouwcentrum in Rotterdam, in this article, which serves as an introduction to a number of articles in this theme issue of BOUW on the new parts of the Bouwcentrum, describes the developments that preceded the realization of the new extensions to the Bouwcentrum complex (situational drawing, photo exterior). He describes in it the history of the older buildings and then describes the program of requirements for the extensions designed by the architectural firm Eijkelenboom and Middelhoek. The consulting architect was architect J.W.C. Boks and the structural engineer was consulting engineering firm Aronsohn N.V.. Construction was carried out by N.V. Aanneming Maatschappij J.P. van Eesteren of Rotterdam. Illustrations: photos/exteriors Building center on Weena - Kruisplein - Diergaardesingel in Rotterdam, arch. new building Eijkelenboom - Middelhoek; reproduction/situation Building center on Weena - Kruisplein - Diergaardesingel in Rotterdam, arch. new building Eijkelenboom - Middelhoek; reproductions/plans Building center on Weena - Kruisplein - Diergaardesingel in Rotterdam, arch. new building Eijkelenboom - Middelhoek; reproductions/sections Bouwcentrum aan Weena - Kruisplein - Diergaardesingel in Rotterdam, arch. new building Eijkelenboom - Middelhoek; photo/interior Bouwcentrum aan Weena - Kruisplein - Diergaardesingel in Rotterdam, arch. new building Eijkelenboom - Middelhoek