§ 4.3. Elevation and construction requirements.

In all SFHAs where base flood elevations have been provided in the FIS or generated by a licensed professional in accordance with section 4.6 of this ordinance, the following provisions shall apply:

A.

Residential construction requirements. New construction or substantial improvement of any residential structure or manufactured home in Zones AE, AH, and A with detailed base flood elevations shall have the lowest floor, including basement, elevated to a minimum of two (2) feet above the base flood level.

B.

Non-residential construction requirements. New construction or substantial improvement of any commercial, industrial, or non-residential building or manufactured home shall have the lowest floor, including basement, elevated a minimum of two (2) feet above the base flood level. Buildings located in AE or AH Zones may be flood-proofed in lieu of being elevated provided that all areas of the building components below the elevation corresponding to the base flood elevation plus a minimum of two (2) feet freeboard are water tight with walls substantially impermeable to the passage of water, and use structural components having the capability of resisting hydrostatic and hydrodynamic loads and the effect of buoyancy. A professional engineer or architect licensed by the Commonwealth of Virginia shall certify that the standards of this subsection are satisfied. Such certification, including the specific elevation (in relation to NAVD88) to which such structures are flood proofed, shall be maintained by the building official.

C.

Space below the lowest floor requirements. In Zones A, AE, AH, and AO, fully enclosed areas of new construction or substantially improved existing structures that are below the regulatory flood protection elevation shall:

1.

Not be designed or used for human habitation, but shall only be used for parking of vehicles, building access, or limited storage of maintenance equipment used in connection with the premises. Access to the enclosed area shall be the minimum necessary to allow for parking of vehicles (garage door), limited storage of maintenance equipment (standard exterior door), or entry to the living area (stairway or elevator).

2.

Be constructed entirely of flood resistant materials below the regulatory flood protection elevation.

3.

Include measures to automatically equalize hydrostatic flood forces on walls by allowing for the entry and exit of floodwaters. To meet this requirement, the openings shall either be certified by a professional engineer or architect licensed by the Commonwealth of Virginia or meet or exceed the following minimum design criteria:

a.

Provide a minimum of two (2) openings on different sides of each enclosed area subject to flooding.

b.

The total net area of all openings shall be at least one (1) square inch for each square foot of enclosed area subject to flooding.

c.

If a building has more than one (1) enclosed area, each area shall have openings to allow floodwaters to automatically enter and exit.

d.

The bottom of all required openings shall be no higher than one (1) foot above the adjacent grade.

e.

Openings may be equipped with screens, louvers, or other opening coverings or devices, provided they permit the automatic flow of floodwaters in both directions.

f.

Foundation enclosures made of flexible skirting are not considered enclosures for regulatory purposes and, therefore, do not require openings. Masonry or wood underpinning, regardless of structural status, is considered an enclosure and requires openings as outlined above.

D.

Manufactured homes and recreational vehicle requirements.

1.

All manufactured homes placed, or substantially improved, on individual lots or parcels or in an existing manufactured home park or in a Recreational Resort Community must meet all the requirements for new construction, including the elevation and anchoring requirements in article 4, section 4.2, and section 4.3 of this ordinance.

2.

All recreational vehicles placed on sites shall either:

a.

Be on the site for fewer than one hundred eighty (180) consecutive days; or

b.

Be fully licensed and ready for highway use (a recreational vehicle is ready for highway use if it is on its wheels or jacking system, is attached to the site only by quick disconnect type utilities and security devices and has no permanently attached additions); or

c.

Meet all the requirements for manufactured homes in article 4 section 4.3 D.1., and the provisions of section 4.9 if located in a V or VE Zone.

(Ord. No. 3309, 11-26-13; Ord. No. 3376, 10-7-14; Ord. No. 3417, 6-2-15)

(Ord. No. 3309, 11-26-13; Ord. No. 3376, 10-7-14; Ord. No. 3417, 6-2-15)