The Gubretas Headquarters Office is located inside Nida Kule building in Göztepe, Istanbul. The idea was to create open, semi-open and closed departments within the current space and the corridors that enable the circulation within the office were extended to the façade as if they are ‘interior streets’ enhancing the daylight diffusion indoors. The corner rooms were allocated for the senior executives in the plan while common meeting rooms were created to provide meetings held by employee and guests. The separating walls of different departments were designed with glass and wood. The walls with wooden ribs were also leaned to the exterior surface acting both as a separating element but also as a visual threshold connecting two glass surfaces. At the same time vertical wooden surfaces extended to cover also the ceiling, resulting in a spatial and visual continuity. The interior streets were furnished with natural stone while wood was preferred for the ceilings and felt was applied on the upper front of the separators, due to the acoustical requirements.