The residential tower mechanical voids text amendment was approved in May 2019 in order to address the issue of developers using excessive voids to boost residential tower heights in predominantly residential areas. Mechanical voids are spaces in towers occupied by equipment, usually heating, ventilation, and cooling systems. (Bloomberg.com, 2019)
Before the May ruling, these voids were excluded from floor area ratio calculations, and there were no specific guidelines or laws regarding the height limits on such spaces. As a result, mechanical voids, which normally would need 10-15 feet of vertical space every 20 stories or so, were being stretched to as high as 350 feet, leading to the now-notorious tower in the park-style super-tall buildings going up in Manhattan and even Brooklyn. (cityrealty.com, 2020)
The text amendment notes that the overuse of mechanical voids has led to residential towers that were “never anticipated by zoning and that disengage with their neighborhoods”. (nyc.gov, 2019)
The amendment includes modifications to R9 and R10 residential districts throughout the city where mechanical voids higher than 25 feet will count as zoning floor area. In addition, any void spaces located within 75 feet of each other will also count towards floor area in order to avoid the clustering of void spaces.
Finally, to address mixed-use buildings, if less than 25% of a building is allotted to non-residential use, then the same 25-foot limit will be applied towards mechanical voids.