noun
roof monitor; monitor roof; lantern roof
Architectural term for a raised section of a roof with windows or louvers for ventilation and light; common in traditional Japanese architecture and industrial buildings.
工場の越屋根から煙が出ている。
Smoke is coming out of the factory's roof monitor.
この古い家には越屋根があって、夏は涼しい。
This old house has a monitor roof, so it's cool in summer.
天窓 is a skylight set into a roof surface, while 越屋根 is a raised structure along the ridge with vertical or louvered openings.
Compound of 越し (こし, 'crossing over' or 'ventilation') and 屋根 (やね, 'roof'). The spelling 越屋根 is standard; 腰屋根 is a less common variant.