This paper reports on experimental process in which a prototype was developed of an interactive design collaboatorium, in cooperation with a group of usability designers. In a longterm research cooperation, this usability group has changed its work practice in order to work in the design collaboratorium. The design collaboratorium was developed to move usability design away from a lab towards an open physical and organizational space where designer, users and engineers meet and collaborate, or work alongside each other. The cooperation between researchers and the usability gruop has resulted in practical experimentation in projects and in design of an experimental design collaboratorium emploing electronic whiteboards, 3D design documentation, etc. This experimental prototype has been evaluated in cooperative workshops. We report on the results of this evaluation.