§ 15-301. Measurement of building height.

(a) In general.

(1) In this subsection, "street wall" means the wall of a building nearest to and facing a street.

(2) For purposes of determining compliance with height limitations, the height of a building is determined by measuring the vertical distance:

(i) from the following, as applicable:

(A) from the mean curb level of the right-of-way on which the property fronts;

(B) if the front wall of the building is not within 30 feet of the curb, from the average elevation of the ground adjoining that wall; or

(C) if the building is in a Regulated Flood-Hazard Area (as defined in and subject to City Code Article 7 {"Natural Resources"}, Division I {"Floodplain Management"}), from the required design-flood elevation (also as defined in and subject to Article 7, Division I); and

(ii) to the following, as applicable:

(A) in the case of a flat roof, to the highest point of the roof that adjoins the street wall; or

(B) in the case of a pitched roof, to the mean height level of the roof as measured between the eaves and the peak in the case of pitched roofs.

(b) Exclusions from height regulations.

The height regulations of this Code do not apply to the following:

(1) belfries, chimneys, cupolas, domes, grain elevators, fire escapes, flagpoles, flues, minarets, monuments, spires, stacks, steeples, ventilators, and utility poles;

(2) water towers or tanks other than those located on the roof of a structure;

(3) bulkheads, cooling towers, elevator enclosures, monitors, elevator or stairway penthouses, skylights, stage towers and water tanks, and air conditioning units, as long as these structures do not occupy more than 25% in the aggregate of the area of the roof of the structure on which they are located;

(4) roof decks, subject to design review;

(5) parapet walls used to screen mechanical equipment, as long as these walls do not exceed the height necessary to screen the mechanical equipment listed in item (3) of this subsection;

(6) any accessory structures in Subtitle 5 of this title that are allowed to exceed height limitations, subject to any limitations imposed by Subtitle 5 of this title; and

(7) rooftop greenhouses, as long as:

(i) the greenhouses do not exceed 15 feet above the applicable district height limit;

(ii) the greenhouses do not occupy more than 50% of the roof area;

(iii) all lighting used to illuminate a rooftop greenhouse is directed and shielded to prevent illumination of any adjacent lots; and

(iv) all exterior lighting complies with the requirements of § 15-505 {"Exterior lighting"} of this title.