§ 231.1. Height regulations and limitations.

A.

Purpose and intent. The intent of the following method of height determination is to permit maximum flexibility in proportioning height and bulk in the architectural design and functional planning of buildings in commercial zones, while assuring that a new building will not deprive existing or potential adjacent buildings of adequate light and air circulation. Terms placed in quotation marks are not found as definitions in Section 101 and apply specifically to this section only. The regulations impose a flexible height "tent" within which the building may rise. Along a street, alley or other public way, such "tent" extends upward at a 45-degree angle toward the subject property from the opposite side of the street or alley along its front, side or rear. The height may be averaged; that is, some portions of the building may project above the "tent," provided other portions, equal in total area, stay proportionately below it. From any rear or side lot line which does not adjoin a street, alley or other public way, a similar "tent" would extend upward more steeply with no averaging of height. These provisions make it practicable to assure adequate light and air to adjacent properties if the building height exceeds 40 feet.

B.

Height determination. The height limitation of a building shall be determined as follows: The "basic height" of the front or rear wall of a building along a street, alley or other public way is determined by a "base line plane" extending upward at a 45-degree angle from a "base line" at the average elevation on the property line on the opposite side of the right-of-way, toward a vertical plane (the "measure plane") on the building line, as defined in Section 101. The horizontal line formed by the intersection of these two planes determines the "basic height," which is the vertical distance above the building line. Regardless of the right-of-way width the "basic height" shall not exceed 100 feet, except as permitted hereinafter as "averaged height," nor shall it be required to be less than 40 feet. In calculating "averaged height" on the "measure plane," the area resulting from multiplying the sum of the heights of portions remaining below the "basic height" by their respective widths shall not exceed the area resulting from multiplying the sum of the heights of portions extending above the basic height by their respective widths. In averaging the heights of component parts of the said wall along a public right-of-way, the total horizontal distances used for averaging shall not exceed twice the "basic height," nor shall the maximum height at the building line, resulting from averaging the height of said wall, exceed twice the "basic height." Any part of the building which is set back from the building line shall not project above a plane or planes sloping inward and upward at a 45-degree angle from the averaged permitted heights at the building line, except that heights of such portions of the building so set back may be used to determine the averaged height by projecting them downward at 45 degrees to the "measure plane ."

C.

On a corner lot a building may have a height along the side street equal to the permitted height of the front wall of the building, determined as provided in Subsection B for a distance from the front corner of the lot equal to the width of the front right-of-way. For the remainder of the building wall along this side of such lot, the permitted height shall be computed in the manner specified in Subsection B.

D.

No part of any building wall adjacent to a side or rear lot line that does not adjoin a street or other public way shall exceed a height of 40 feet above the average ground level along such wall, except that any part of such wall may exceed that height, provided that no portion of the building would project above a plane sloping inward and upward from the lot line at the rate of one-foot horizontally for each five feet of vertical distance above said average ground level.