32A-144 1509.2 Penthouse1509.2 Penthouses. A penthouse or penthouses in compliance
with Sections 1509.2.1 through 1509.2.4 shall be considered as
a portion of the story below.
This section introduces the requirements necessary
for a penthouse to be considered as a portion of the
story directly below. Section 1509.2.1 contains height
limitations, Section 1509.2.2 contains area limitations
and Section 1509.2.3 contains use limitations.
1509.2.1 Height above roof. A penthouse or other projection
above the roof in structures of other than Type I construction
shall not exceed 28 feet (8534 mm) above the roof where used
as an enclosure for tanks or for elevators that run to the roof and
in all other cases shall not extend more than 18 feet (5486 mm)
above the roof.
The heights of roof structures are not limited provided
the building is of Type I construction. For other types of
construction, the roof structure is limited to 18 feet
(3658 mm) in height unless it encloses tanks or elevators
that extend to the roof, for which the maximum
height is 28 feet (8534 mm). If the height exceeds that
permitted, the roof structure should be counted as,
and meet all the requirements of, a story.
1509.2.2 Area limitation. The aggregate area of penthouses
and other rooftop structures shall not exceed one-third the area
of the supporting roof. Such penthouses shall not contribute to
either the building area or number of stories as regulated by
Section 503.1. The area of the penthouse shall not be included
in determining the fire area defined in Section 902.
The area of the penthouse is also limited to one-third
of the roof area. If the area of the penthouse exceeds
one-third the roof area, regardless of height, then the
penthouse must be considered a story.
1509.2.3 Use limitations. A penthouse, bulkhead or any other
similar projection above the roof shall not be used for purposes
other than shelter of mechanical equipment or shelter of vertical
shaft openings in the roof. Provisions such as louvers, louver
blades or flashing shall be made to protect the mechanical
equipment and the building interior from the elements. Penthouses
or bulkheads used for purposes other than permitted by
this section shall conform to the requirements of this code for
an additional story. The restrictions of this section shall not
prohibit the placing of wood flagpoles or similar structures on
the roof of any building.
The use of the penthouse is also limited. Regardless
of height or area, roof structures used for anything
except sheltering mechanical equipment or vertical
shaft openings must be considered as an additional
story.