The construction area is in the central part of the green belt at the foot of Mount Sljeme; it is surrounded by residential buildings, as well as by accompanying and public facilities. The construction lot is trapezoidal in shape and the height difference on the inclined slope is about 4 m. The central mass of the structure is shifted by half a storey, adapting to the configuration of the terrain. The floor-plan organization of apartments around the central vertical communication follows the changes at each level and through spatial interrelations realizes the different possibilities of using particular residential zones. The spaces are not clearly divided, but through their structure and the form of the floor-plan, they define separate units that can be interpreted in different ways in everyday usage. The fronts of the buildings resolve the relationship with their environment by varied treatment. The entrance front is open and vertically divided, featuring stressed window jambs. By altering the level of glass transparency, the openness of the front changes. The south-west front of the living rooms has protruding, two-metre-deep terraces and a glass wall along its entire length. The other two sides are conceived as chromatically marked walls with openings.