The 'more house' by spanish firm acha zaballa arquitectos is located in a developing low-density residential area known as montealegre in the outskirts of castro-urdiales. the primary strategy in the design was to optimize efficiency in space as much in the exterior landscaping as in the interior organization of program. much of the site is excavated, defined by an irregular angular retaining wall. apart from creating a protected exterior garden out of the site of neighbors, it also allows the masonry structured house to take on a vertical aspect as the basement level can receive natural light and fresh air. following the form of three wood-clad stacked boxes, the alternating nature of the dwelling creates resultant spaces that support extra activities. overhangs provide shade and cover in certain outdoor areas whereas the upper side of the volume now creates a south-facing terrace. each mass contains two equally sized windows that offer views in differing directions. a central staircase runs like a spine through all the levels as the program develops on either side of it, lending to maximum efficiency in circulation.