All measurements of height above curb level, base plane, base flood elevation, grade or other similar ground related datum, shall be from the flood-resistant construction elevation. This provision shall not apply to buildings that are accessory to single- or two-family residences, or to fences, signs not affixed to buildings, or other structures that are not buildings.
In R3, R4-1 and R4A Districts within lower density growth management areas, the maximum perimeter wall height shall be 21 feet above the flood-resistant construction elevation or 26 feet above grade, whichever is greater.
Where different flood-resistant construction elevations apply to different portions of a building, the highest of such flood-resistant construction elevations may apply to the entire building.
For buildings located partially within and partially outside of the flood zone, all measurements of height shall be in accordance with only one of the following provisions:
(a) the flood-resistant construction elevation shall apply to the entire building;
(b) the height of the portion of the building within the flood zone shall be measured from the flood-resistant construction elevation, and the height of the portion of the building outside of the flood zone shall be measured from an elevation determined in accordance with the underlying applicable regulations; or
(c) the elevation of each such portion of the building from where height is measured shall be multiplied by the percentage of the total lot coverage of the building to which such elevation applies. The sum of the products thus obtained shall be the elevation from which the height of the entire #building is measured.