Kostolačka 21 is a project of adapting a space into an apartment for a family of two. The project's core concept was to adapt the apartment in an economical and efficient manner which complies with the needs of contemporary living. One of the key elements of the architecture of this space was the design of an open-space living area with the kitchen, and a kitchen island as binding element of the day-zone areas.

Dissolving the boundaries between spaces and its functions was established by distorting the common perception of what architectural space is. The kitchen and living room are divided yet connected by a singular element – a kitchen island, which symbolically and spatially develops the theme of a broadened communication, specific for Belgrade residential architecture. The bedrooms of the apartment are designed as individual spaces, while the contrasts and minimalist feel of both the day and night areas are ennobled through different ceiling heights.

Relative to its surface, each of the individual rooms has an appropriate ceiling height that follows the geometry of the roof slope. Purified geometry and volumetry combined with light (both natural and artificial) and accented clarity and simplicity, both in detail and in the organization of the space itself, rest the user from the redundant and the unnecessary, indulging the user in a game of light and space. On the other hand, the functional connection of the volumes allows a continuous movement through the space, in which the kitchen island is a central element where the continuous flow starts and ends.