For all flood-resistant buildings, the definition of floor area may be modified in accordance with the provisions of this Section.

(a)        Entryways

In all districts, for buildings other than residential buildings with enclosed entryways below the first story above the flood elevation, up to 100 square feet of such entryways may be excluded from the definition of floor area for each foot of difference between the first story above the flood elevation and the level of the adjoining sidewalk, provided such floor space complies with the flood-resistant construction standards for dry-flood-proofing up to the flood-resistant construction elevation or higher. However, no more than a maximum of 500 square feet may be excluded from the definition of floor area for each entryway.

Such exempted floor space shall be considered floor area for the purposes of satisfying other ground floor use regulations of this Resolution, including, but not limited to, limitations on floor area for certain uses, parking wrap and screening requirements, and requirements for floor area at the ground floor.

(b)        Modifications to attic allowances for residential buildings

In R2X, R3, R4, R4A, and R4-1 Districts outside of lower density growth management areas, the provisions of paragraph (a) of Section 23-142 (Open space and floor area regulations in R1 and R2 Districts with a letter suffix and R3 through R5 Districts) shall be modified to allow the floor area ratio set forth in the table of such Section to be exceeded by 20 percent provided that any such increase in floor area is located in any portion of a building covered by a sloping roof that rises at least three and one-half inches in vertical distance for each foot of horizontal distance.

(c)        Flood-proofed ground floors

(1)        For buildings along primary street frontages, or portions thereof, as defined in Section 64-11, floor space located below the first story above the flood elevation and within 30 feet of the street wall along such primary street frontage may be excluded from the calculation of floor area, provided that:

(i)        such floor space complies with the flood-resistant construction standards for dry-flood-proofing up to the flood-resistant construction elevation or higher;

(ii)        the level of the finished floor of such floor space is located no more than two feet above nor two feet below curb level;

(iii)        such floor space shall be limited to non-residential uses other than accessory parking or public parking garages and subject to the minimum depth requirements set forth in Section 37-32 (Ground Floor Depth Requirements for Certain Uses);

(iv)        ground floor level street walls shall be glazed in accordance with the provisions set forth in Section 37-34 (Minimum Transparency Requirements); and

(v)        for developments, the level of the first story above the flood elevation is 13 feet or more above the level of the adjoining sidewalk.

However, such floor space shall be considered floor area for the purposes of satisfying other ground floor use regulations of this Resolution, including, but not limited to, limitations on floor area for certain uses, parking wrap and screening requirements, and requirements for non-residential floor area at the ground floor.

(2)        In all districts, floor space located below the first story above the flood elevation may be excluded from the calculation of floor area provided such floor space complies with the flood-resistant construction standards for wet-flood-proofing up to the flood-resistant construction elevation or higher.

(d)        Floor area for existing buildings

For zoning lots containing buildings existing prior to May 12, 2021, as an alternative to the floor area regulations of this Chapter, the amount of floor area allocated to a basement or cellar in such existing building may be determined in accordance with how those terms were defined prior to May 12, 2021.