noun
upper floor; high floor
Refers to floors high up in a multi-story building, typically a high-rise. Often used in real estate, views, or safety contexts.
高層階の部屋は眺めがいい。
Rooms on the upper floors have a good view.
地震のとき、高層階ほど揺れが大きい。
During an earthquake, the higher the floor, the stronger the shaking.
高層ビル is a high-rise building itself, whereas 高層階 refers specifically to the upper floors within such a building.
Compound of 高層 (high-rise, upper level) and 階 (floor, storey).