Daylight Plane. A daylight plane for the main dwelling unit shall begin at each side property line, shall extend directly upwards above the natural grade of each side property line for a distance of twenty (20) feet minus the width of the adjacent required yard, and shall then slope inwards towards the interior of the lot at a thirty-four (34) degree angle. As used in this section, the natural grade of a side property line is the average grade of the highest and lowest points of the natural grade of the lot at the side property line. No portion of the structure shall intrude beyond the daylight plane except for dormers and gables as provided below and chimneys, vents, antennas, flues, and solar collectors.
Gables and dormers may intrude into the daylight plane of a lot that is ten thousand (10,000) square feet or less. The permitted intrusion shall decrease on an even gradient from ten (10) feet in the case of a five (5) foot required side setback to no permitted intrusion in the case of an eight (8) foot required side setback. Thus the permitted intrusion will be six (6) feet, eight (8) inches in the case of a six (6) foot required side setback, five (5) feet in the case of a six and one-half (6.5) foot required side setback, and three (3) feet, four (4) inches in the case of a seven (7) foot required side setback. Calculations of the permitted intrusion shall include fractional computations when necessary to maintain the even gradient. Gables and dormers may intrude into the daylight plane on one (1) side of a lot only. The gable or dormer must not extend beyond a triangle described as follows:
(A) The base of the triangle is the line formed by the intersection of the building wall with the daylight plane;
(B) The aggregate length of the bases of all triangles intruding into a daylight plane shall not exceed thirty (30) feet; and
(C) The triangle must be entirely within the maximum building height.