It seems that this construction is made out of separate buildings. But further below you can see that this building is actually one unit consisting of six interlocking parts.
A study devised by Alventosa Morell Architects created a compatible and energy efficient house not far from Barcelona. This house blends perfectly with surrounding trees and hills. A great deal of thought has obviously been put into this design which is heated by one radiator in winter. Special glass panels are used to retain a great amount of heat.
You can find impressive pictures of this house below.
Source: plataformaarquitectura.cl