The opportunity, repeated over a short but continuous span of time, to work on the routes of vertical circulation of a number of interiors has given the studio the chance to develop a specific approach to the construction of space in a coherent and experimental manner. A clearly formulated theorem was interpreted in three variations, conditioned by very different geographical and social contexts. Operating within a “series”, in which the relationship of constants and variables is carefully calibrated, reveals the tectonic and environmental implications of the different designs.