Highly critical piece about the predicate experimental granted to homes of the Hartsuykers. According to the author, it is merely different from usual and unproven to be better. De Jonge is generally critical of the methods of the committee charged with evaluating experimental housing projects. The criteria are arbitrary and the composition of the committee is one-sided. Illustrations: floor plans and cross-sections/Flat building 't Duifje Arnhem; floor plans and cross-sections/Flat building Schroefhuis Rapenburgerstraat Amsterdam; cross-sections, floor plans (3), interior drawings/Portico spiral house; floor plans (3), cross-sections/Small single-family house; interior drawings/Flat building Schroefhuis Rapenburgerstraat Amsterdam