Three Phases have ended in the MAA program, This week students have gone back to work on their first introductory design course – ArboReal House Design – this time they do their tree house in a one to one scale. The Design course required students to study a tree, its functions and geometries to create a new hybrid of botanical species (partially natural and partially artificial) where tree and house structure work as a single organism. Day 1 Site located in the House of Can Valldaura, in the Collserola Park,  Cerdanyola de Vallés, Students with IaaC Director Vicente Guallart, faculty Areti Markopoulou, Gerard Passola, Luis Fraguada and  Meg Lowman,Biologist, Canopy  www.canopymeg.com divided in groups to choose a site, locate a tree, and make a model of a tree house which suited best for their tree.After students made small prototypes of their proposals; components were taken from every group to decide on how the tree house will look like. Day 2 Tensegrity structure was the decided system to build the house. Since this is flexible enough to be built anywhere on any tree, Students with faculty located their house according to its location, topography and view. Materials were also selected – Wood, rope, Pine cones, branches, shrubs and twigs. The house was going to be made between three pine trees. Day 3 With Assistants from Dr. Gerard passola, the tree house structure was started. All students were assigned to make various work. some started joining the pine cones for the facade, some started to weave the base. some started to make the facade, and some collected broken pieces of branches and shrubs which are serving as materials. Day 4 On the last day of the workshop, faculty and students decided on the type of roof structure they will put up. This marked the completion of their tree house, which will serve three people (maximum), highleveled enough to enjoy a view from the forest. The workshop ended with a barbeque at the house of Can Valldaura.