The AC Papalotes, commissioned us to design a new classroom for their school based in Oaxaca. Papalotes is a school which use the Waldorf educational method, it means that the building needs to be just “particular”: mainly without right corners in order to keep energy flowing through the space. We adopted a wooden reciprocal frame to design a roof structure completely independent from the walls. It suits perfectly with a low badge and short time construction requirements. We sort out the absence of right angle with a sneaky bahareque wall, finally plastered with lime. The 75% of the building has been built by a 25 people, who took part a sequence of three workshops.