A design studio and a parallel research project focused on transformable fabric architecture. To facilitate a part of this work, computer based shape generation tools were used to optimize the placement of thin-film photovoltaic cells onto a transformable roof structure. In addition, the tension membrane fabric is rigged in a way that is similar to a sailing boat. The fabric is set into position by winches and cables. The winches are hand-operated so as to lower the overall energy cost. The initial computer models proceeded concurrently with the mockup of small-scale physical prototypes. In addition, the author used an open source programming language to implement a particle spring real time simulation of the fabric shapes. The simulation included a three-dimensional graphical representation of solar insolation and helped to further determine the physical geometry of the project. One of the goals was to evaluate whether larger transformations to the structure as a whole or smaller movements in the fabric would help to optimize the solar insolation benefits. As the examination of potential forms narrowed down to classical saddle shapes, the practical details of rigging the fabric imposed further limitations on its transformable nature. This paper is focused on how modelling with ad hoc tools and especially real-time computer simulation influenced the direction of the work.