This research consists of 3 parts/scales, combined in a single methodology: 1. The regeneration and redevelopment of (structurally) vacant office buildings, preparing a base ‘support’ building for 2. A customized housing solution, answering the diverse requirements households have regarding their living conditions by giving them the opportunity to spatially design their own home – with constraints – as the current postwar housing stock doesn’t provide a viable answer and; 3. A given set of reference points for a design for a technical construction system that facilitates the spatial mass customization of a single dwelling, taking into account design for manufacturing and (dis)assembly strategies for a durable system with relatively low life-cycle embodied energy due to the minimization of the recurring embodied energy. The 3 different scale levels combine in an open building approach, where a generic top-down structural frame is being designed as an architectural entity that facilitates an orchestrated bottom-up redevelopment of an office building ensuring individual customization and requirements by using a prescribed modular construction system with customization features.