Central Business Districts: Residential Tower Mechanical Voids Policy Change
While releasing the proposed policy change, DCP will continue to engage with stakeholders before filing a formal zoning application.
THE ISSUE: Risk of Excessive Voids
The NYC Department of City Planning (DCP) proposes a policy change for residential buildings in Special Purpose Districts within central business districts (CBDs). The proposed policy change, which follows the previously adopted citywide Residential Tower Mechanical Voids Text Amendment, is intended to:
- Discourage the use of excessively tall mechanical floors that artificially elevate upper-story residential units above the surrounding context.
- Maintain the necessary flexibility required for the unique site conditions found in CBDs.
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THE SOLUTION: Policy Changes to CBD Special Purpose Districts
DCP’s proposal applies restrictions to residential tower mechanical spaces in R9 and R10 Districts, and their equivalent commercial districts, in Special Purpose Districts within CBDs to:
- Discourage mechanical space taller than 35 feet on floors occupied predominantly (more than 50 percent) by mechanical space.
However, to account for unique site constraints found in CBDs, for the portion of a building below 150 feet, “predominantly” would mean 66 percent of a floor.
- Discourage the clustering of mechanical spaces in a way that unduly pads building heights.
Any mechanical spaces located within 75 feet of each other will count as zoning floor area.
- Address mixed-use buildings.
Non-residential mechanical space will be subject to the same 35-foot height limit if non-residential uses occupy less than 25 percent of a building.
THE COMPARISON: Between Residential Buildings Within CBDs and Outside of CBDs
Residential buildings in CBDs are often substantially larger and warrant a different treatment than those in high density areas covered under the previously adopted text amendment.
- Due to the higher density and built-out nature of CBDs, residential buildings on constrained sites often require mechanical spaces to be stacked to maximize efficiency.
- Large mechanical spaces are typically located in the cellar of buildings, but in CBDs, they are often positioned higher within a building due to subgrade constraints, flood resiliency, or active commercial or community spaces.
- Newer and aggressive energy-efficiency standards, such as Local Law 97 (adopted in May 2019), require increasingly large mechanical equipment to maximize energy efficiency.
THE GEOGRAPHY: R9 and R10 Zoning Districts
The focus is on R9 and R10 Districts and their equivalent commercial districts where residential towers are permitted within the Special Purpose Districts of Lower Manhattan, Midtown, Hudson Yards, Downtown Brooklyn and Long Island City.
The proposal is also intended to apply the previously adopted citywide residential tower mechanical voids provisions to R9D and R10X Districts, and their equivalent commercial districts that permit residential towers.
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