A challenging site was completed by placing the addition along the very edge of the available plot creating the curving backbone of the building while preserving as much schoolyard as possible. Hallways are dedicated to teaching and studying and classrooms can be combined by opening pedagogical doors in dividing walls. Massive clay block construction was chosen to reduce any risks to indoor air quality or other construction faults and by using breathing mineral wall finishes and paints we preserved the good indoor-climate regulation properties in the structure. Facades are clad in bricks and zinc - materials derived from the main building.