The extension is a volume with a frame of cross-laminated timber panels, clad in larchwood louvers and held up by the loadbearing walls of a 19th-century villa beside it, in the Basque town of Usurbil, Gipuzkoa province. The intervention stretches on to the edges of the site, forming small voids for light and air to come in. The location of the premises, between two streets set at different levels, made it possible – through the building’s new section – to access most parts of the program without necessarily using the elevator. Fragmented into a discontinuous formation of planes, the green roof provides a public space at the level of the main entrance. The original floor of the villa harbors the larger classrooms.