When an extended Spanish family decided to build a treehouse for their five grandchilden on their estate in Extremadura, they knew they wanted to protect their beloved "encinas" (holm oak trees). So they contacted the design firm Urbanarbolismo whose primary focus is "integrating architecture with nature."
Rather than design a treehouse to fit the family, the architects designed one to fit the tree. It fits so well, in fact, that not a single branch of the centuries-old oak had to be removed, nor was a single nail or screw driven into one.
To create a treehouse that was perfectly molded to the tree, the architects first created a very exacting 3D model of the oak. The final project seems fluid with the tree. Artificial roots, in the form of wooden beams, help support the deck. Branches leak through the roof providing a canopy of foliage and shade to the small fort.
Even the small home's materials are adapted to the environment and provide a perfect camouflage. The roof is made of local shrubs, or "brezo" (heath) and the exterior walls are clad in the bark of local cork oak trees (cork bark can be removed every nine years and will regenerate).