BACSAC ® was born from the encounter between Virieu Godefroy, Louis Fleurieu Desurmont and Virgil. Together, they seek an alternative solution to the constraints posed by the construction of a roof terrace in town: the difficulty of transport, excess weight, but also poverty of the offer price for the containers. How to reverse the tendency to pay more container than the contents? How to make mobile development that is often immobile because of its weight and its rigidity? How to create a space planted at lower cost?