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1 4.O8.240 Specific sta nda rds. <br />ln all areas of special flood hazards where base flood elevation data has been provided as set forth <br />in KCC 14,08.040, Basis for establishing the areas of special flood hazard, or KCC 14.08.120, Use of <br />other base flood data, the following provisions are required. (Ord.200103; Ord.93-18 $ 5.2, 1993). <br />1 4.08.250 Residential construction. <br />1 . ln AE and A1 -30 zones, or other A zoned a reas where the BFE has been determined or can be <br />reasonably obtained, new construction, substantial improvement, and reconstruction due to <br />substantial damage of any residential structure shall have the lowest floor, including basement, <br />elevated one foot or more above the base flood elevation. <br />2. Fully enclosed areas below the lowest floor that are subject to flooding are prohibited, or if used <br />solely for parking access or storage shall be designed to automatically equalize hydrostatic and <br />hydrodynamic flood forces on exterior walls by allowing for the entry and exit of floodwaters. <br />Designs for meeting this requirement must either be certified by a registered professional <br />engineer or architect or must meet or exceed the following minimum criteria: <br />a. A minimum of two openings having a total net area of not less than one square inch for <br />every square foot of enclosed area subject to flooding shall be provided. <br />b. The bottom of all openings shall be no higher than one foot above grade. <br />c. Openings may be equipped with screens, louvers, or other coverings or devices provided <br />that they permit the automatic entry and exit of floodwaters. <br />d. A garage attached to a residential structure, constructed with the garage floor slab below <br />the BFE, must be designed to allow for the automatic entry and exit of floodwaters. <br />e. Because of hydrodynamic loads, below grade crawlspace construction is not permitted in <br />areas with flood velocities greater than 5 feet per second unless the design is approved by <br />a registered architect or licensed engineer. <br />3. Any interior or exterior building utility systems must be elevated one-foot or more above the <br />Base Flood Elevation (BFE) with the exception of utility meters and equipment specifically <br />designed to withstand inundation according to the standards of the lnternational Residential <br />Codes and the NFIP . <br />4. Portions of buildings below the BFE must be constructed using methods and practices that <br />minimize flood damages, and with materials resistant to flood damage. This includes any joists, <br />pony walls, beams, posts, insulation, wall coverings, wall sheathing or other materials that <br />extend below the BFE. <br />5. The elevation of the interior crawlspace grade (inside of the foundation walls in crawlspace <br />construction) must be at or above the lowest elevation of the exterior grade. Below-grade <br />crawlspace foundations will be allowed only if all of the following conditions are met, in addition <br />to the minimum criteria set forth above in this subsection: (buildings that have below-grade <br />crawlspaces may have higher flood insurance premiums than buildings that have the preferred <br />crowlspace construction, with the interior elevation at or above the lowest adjacent exterior grade). <br />a. The interior grade of the crawlspace (below the BFE) must not be more than 2 feet below <br />the lowest adjacent exterior grade. <br />b. The height of the below-grade crawlspace, measured from the interior grade of the <br />crawlspace to the top of the crawlspace foundation wall must not exceed 4 feet at any <br />point.