The nursery school had to occupy the existing premises but it needed more space for the multipurpose classroom, the utility room, the staff restroom and the playground. An adjoining plot was used to build a new building that fulfilled the program. The existence of urban services in the subsoil of this plot forced us to design a light ephemeral structure with no foundations that could be easily dismantled. Built with plywood panels, tubular steel frames and concrete sleepers underneath, it is connected with the rest of the nursery by a covered passageway and it opens to the playground at the other side.