It is a sustainable construction system made by cross-laminated timber glued with high pressure into boards of 3, 5 and 7 layers, joining the longitudinal and transverse layers. 
It is a system that allows you to create spaces with large spans, eliminates columns, supports high loads, is fireproof, has sound and heat insulating properties, controls the air humidity inside the building.
In this specific project they were used in the structure of the floors, walls and roofs.