The existing building of the elementary school Čavle was built on the edge of dense wood in a public area (kindergarten, local government, ambulance). Location of school extension is a small hill with the height difference between the highest and lowest point of 4.50m. The urban surrounding is typical Croatian suburban architecture, residential and mixed use, with vivid colors facades. School extension consists of 8 new classrooms with accompanying contents. The new wing, located along the northeastern edge of the newly formed particle, connects to the existing building at its entrance. The wing is oriented to the southwest to use the most favorable orientation for new classrooms due to illumination and view towards the dense greenwood. The functional extension is divided into two floors, basement and ground floor. By placing an extension along the edge of the hill, the school is placed at the highest position, but articulates all the surrounding contents and forms an organized urban plot: the entrance to the school, the communication space between the kindergarten and the school, the school playground and a clearly defined entrance to the existing school building.