This is a 10-storey apartment with a height of 30m, located in the city center. In order to secure openness on the two sides of the site facing the streets, two Reinforced Concrete walls are set up facing the adjacent properties, a fire stair is placed in the center, and a timber floor slab with a 2-hour fire resistance rating spans between them. By developing a pump-up type water supply unit, the maximum ceiling height is achieved within a small floor-to-floor height without increasing the structural floor depth.