New construction or substantial improvements of elevated buildings that include fully enclosed areas that are below the regulatory flood protection elevation shall not be designed to be used for human habitation, but shall be designed to be used only for parking of vehicles, building access, or limited storage of maintenance equipment used in connection with the premises, be constructed entirely of flood resistant materials below the regulatory flood protection level in A, AO, AE, and A1-30 Zones and meet the following design criteria:
(A) Measures for complying with this requirement shall be designed to automatically equalize hydrostatic flood forces on exterior walls by allowing for the entry and exit of floodwaters. To meet this requirement, the foundation must either be certified by a professional engineer or architect or meet the following minimum design criteria:
(1) Provide a minimum of two openings on different sides of each enclosed area subject to flooding;
(2) The total net area of all openings must be at least one square inch for each square foot of each enclosed area subject to flooding;
(3) If a building has more than one enclosed area, each area must have openings on exterior walls to allow floodwater to directly enter;
(4) The bottom of all required openings shall be no higher than one foot above the adjacent grade; and
(5) Openings may be equipped with screens, louvers, or other opening coverings or devices provided they permit the automatic flow of floodwaters in both directions.
(6) Foundation enclosures.
(a) Vinyl or sheet metal skirting is not considered an enclosure for regulatory and flood insurance rating purposes. Therefore, such skirting does not require hydrostatic openings as outlined above.
(b) Masonry or wood underpinning, regardless of structural status, is considered an enclosure and requires hydrostatic openings as outlined above to comply with this chapter.
(B) Access to the enclosed area shall be the minimum necessary to allow for parking of vehicles (garage door) or limited storage of maintenance equipment used in connection with the premises (standard exterior door) or entry to the living area (stairway or elevator). The interior portion of such enclosed area shall not be partitioned or finished into separate rooms, except to enclose storage areas.
(Ord. passed 4-2-2007; Ord. passed 6-7-2021)