upper floor; floor above; upstairs
Refers to a floor above the current one in a building. Often used in contrast with 下階 (lower floor).
See also: 下階
上階から足音が聞こえる。
I can hear footsteps from the floor above.
このビルの上階はオフィスになっている。
The upper floors of this building are offices.
Compound of 上 (じょう, 'upper') and 階 (かい, 'floor'). The reading じょうかい follows standard on'yomi patterns.