DictionarypenthouseRooftop structure
noun

penthouse

A room or enclosed structure built on a building's roof.

A small penthouse encloses the rooftop machinery.

Etymology

The word developed from a term for an attached shed or lean-to, later reshaped as though it contained house. Its meaning shifted to a structure or dwelling on a building’s roof.

More examples

  • The architect drew the elevator penthouse above the roofline.
  • Workers entered the service penthouse to inspect the equipment.
  • The plans included a rooftop penthouse for ventilation equipment.

Forms

penthouse · penthouses

Similar words

rooftop enclosure
A plain description without the apartment sense.