Windows location, size and operable area determine whether a proposed space can be considered as a habitable or occupiable room.
Where the 2022 NYC Building Code applies, habitable rooms require natural light through exterior glazed openings with Section BC 1205 establishes a minimum net glazed area of 10% of the room’s floor area, subject to its requirements and exceptions. Natural ventilation requirements depend on the amount of openable window area.
When an Owner wants to divide one large room into two rooms, create another bedroom, relocate partitions, or substantially change an existing floor plan, our architectural team determines whether the resulting rooms satisfy the applicable light, air and dimensional requirements.
The code distinguishes habitable spaces from other occupiable spaces. Habitable spaces include bedrooms, living rooms, studies, recreation rooms, kitchens, dining rooms and similar spaces within a dwelling unit.
Habitable rooms are subject to requirements for natural light, ventilation, minimum area and dimensions. Under the 2022 Building Code where applicable, a habitable room generally must contain at least 80 square feet, with specific exceptions, and at least one habitable room in a dwelling unit generally must contain 150 square feet. Existing multiple dwellings are also governed by the Multiple Dwelling Law and applicable prior-code provisions, depending on the building and scope.
This is why calling a space a “home office,” for example, does not by itself resolve building code requirements relative to the floor plan layout. The proposed use, configuration, building history and applicable regulations shall be evaluated.