In accordance with Section 312 of the Building Code, Utility
and Miscellaneous Group U includes buildings and structures that are
accessory in character and miscellaneous structures not classified
in any specific occupancy in the Building Code, including, but not
limited to, agricultural buildings, aircraft hangars (accessory to
a one- or two-family residence), barns, carports, communication equipment
structures (gross floor area less than 1,500 square feet), fences
more than six feet high, grain silos (accessory to a residential occupancy),
livestock shelters, private garages, retaining walls, sheds, stables,
tanks, and towers.
Accessory structures in the SFHA shall comply with the elevation requirements of Article
IV, §
135-4.3C or, if not elevated or dry floodproofed, shall:
A. Be wet floodproofed, via variance, for structures no more than 600
square feet. Accessory structures more than 600 square feet must be
elevated or dry floodproofed;
B. Not be used for human habitation;
C. Be usable only for parking of vehicles and limited storage;
D. Be constructed with flood-damage-resistant materials below the base
flood elevation;
E. Be constructed and placed to offer the minimum resistance to the
flow of floodwaters;
F. Be anchored to prevent flotation;
G. Have electrical service and mechanical equipment elevated to or above
the base flood elevation;
H. Be provided with flood openings which shall meet the following criteria:
(1)
There shall be a minimum of two flood openings on different
sides of each enclosed area; if a building has more than one enclosure
below the lowest floor, each such enclosure shall have flood openings
on exterior walls.
(2)
The total net area of all flood openings shall be at least one
square inch for each square foot of enclosed area (nonengineered flood
openings), or the flood openings shall be engineered flood openings
that are designed and certified by a licensed professional engineer
to automatically allow entry and exit of floodwaters; the certification
requirement may be satisfied by an individual certification or an
evaluation report issued by the ICC Evaluation Service, Inc.
(3)
The bottom of each flood opening shall be one foot or less above
the higher of the interior floor or grade, or the exterior grade,
immediately below the opening.
(4)
Any louvers, screens or other covers for the flood openings
shall allow the automatic flow of floodwaters into and out of the
enclosed area.
Utility and Miscellaneous Group U buildings and structures,
including substantial improvement of such buildings and structures,
shall be anchored to prevent flotation, collapse, or lateral movement
resulting from flood loads, including the effects of buoyancy, during
conditions of the base flood.
Utility and Miscellaneous Group U buildings and structures,
including substantial improvement of such buildings and structures,
shall be elevated such that the lowest floor, including basement,
is elevated to or above the base flood elevation in accordance with
ASCE 24.
Fully enclosed areas below the design flood elevation shall
be constructed in accordance with ASCE 24.
Flood-damage-resistant materials shall be used below the design
flood elevation.