roof deck
The main roof or uppermost roof is equipped for regular access by tenants or visitors.
A roof deck is any configuration of the uppermost roof of a building, or the main roof around a mechanical penthouse, which allows regular access by the building's users, tenants, or visitors. Normally this entails a fence or other barrier around the perimeter for safety and easy access by a stairway or elevator. A roof deck often but not always features a finished floor on the roof for easy walking, and/or furniture and amenities for enjoyment of views and open air.
A roof deck may also serve as a sundeck. In some cases it can provide amenities similar to a hospitality room, with bar service and availability for private parties.
Regular access by users distinguishes a roof deck from a roof reached only for maintenance. Its position on the uppermost or main roof is part of the definition; furniture, sunbathing, and party facilities are possible additions rather than requirements for every roof deck.
