Special Mixed Use District (MX): How M1/R Zoning Works

Mapped in 25 neighborhoods from Port Morris to DUMBO to Kingsbridge Heights, MX is New York's main tool for legal live-work blocks.

What the Special Mixed Use District is

The Special Mixed Use District, shown on zoning maps as "MX" with a number, lets homes and light industry sit side by side on the same block and even in the same building. Its stated purposes include encouraging investment in mixed residential and industrial neighborhoods and promoting "the opportunity for workers to live in the vicinity of their work" (ZR 123-00). In each MX district an M1 district is paired with a residence district, as indicated on the zoning maps, and the residence district can never be R1 or R2 (ZR 123-10). A typical map label reads like an M1 district and an R district joined together, and both halves matter.

Where it is mapped

Source: ZR 123-90, which lists each MX district with the date it was established. Exact boundaries are on the zoning maps.

Uses: both lists, with conditions

• All uses permitted in the paired residence district and all uses permitted in the paired M1 district are allowed, except as modified by the chapter (ZR 123-20).
• Some M1 rules are tightened: Use Group IX(B) storage uses are not permitted, and Use Group X production uses follow the C7 rules of ZR 32-20 instead of M1 rules, without the ground-floor size limit (ZR 123-21).
• Commercial and manufacturing uses subject to ZR 123-22 must meet M1 performance standards, and may share a building or a common wall with homes, or with community facilities that have sleeping accommodations, only if they hold no "A", "B" or "C" environmental rating for permitted process equipment and do not have to file a Risk Management Plan for Extremely Hazardous Substances (ZR 123-22).
• In a building with homes, commercial or manufacturing uses go only on stories below the lowest story with dwelling units, unless there is no access between the uses on residential floors and other conditions are met (ZR 123-31).
• A home occupation may exceed 1,000 sq ft and employ up to three people who do not live there, and an accessory dwelling unit of up to 1,200 sq ft gross is allowed for a permitted business (ZR 123-11).

Noise and ventilation for new homes

All new dwelling units in an MX district need at least 35 dB(A) of window wall attenuation, to keep interior noise at 45 dB(A) or less with windows closed, plus an alternate means of ventilation. The Office of Environmental Remediation can modify this if the alternative is equally protective (ZR 123-32).

Floor area: which half sets which number

Sources: ZR 123-621, 123-622 and 123-623; ZR 43-12. Where the residence district is R3, R4 or R5, the mixed-building total is the greater of the M1 non-residential FAR or 2.50 for qualifying residential sites in the Greater Transit Zone (outside it: 1.50 in R3, 2.00 in R4, 2.50 in R5) (ZR 123-623). In R3 to R5 pairings inside the Greater Transit Zone, residential-only lots use the R5 qualifying residential site FAR (ZR 123-622).

Height, yards and coverage

• R6 to R12 with a letter suffix (for example R6A or R7A): base and building heights come from the ZR 23-432 table for that district (ZR 123-652).
• R6 to R12 without a suffix: MX has its own table. Examples: R6 and R6-1, base 40 to 65 ft and building height 125 ft; R7-1 and R7-2, base 40 to 85 ft and 155 ft; R8, base 60 to 105 ft and 215 ft; R10, base 60 to 155 ft and 355 ft. These heights may be exceeded by 25 percent if each story above the limit is no more than 90 percent of the gross area of the story below (ZR 123-652).
• R3, R4, R5 pairings: maximum base and building heights for qualifying residential sites are 35 and 45 ft in R3, 35 and 55 ft in R4, and 45 and 65 ft in R5; in the Greater Transit Zone, R5 height rules apply (ZR 123-64).
• Yards: no front or side yards are required; a side open area for multiple dwellings, if provided, must be at least five feet wide. For mixed buildings, the rear yard is provided at the lowest story with dwelling units (ZR 123-631).
• Lot coverage: residential-only zoning lots follow residential coverage rules; other zoning lots have no lot coverage requirement (ZR 123-632).
• Optional bulk rules: the optional bulk provisions of ZR 23-70 do not apply in MX districts (ZR 123-61).

A worked example

A 5,000 sq ft lot in an MX district where M1-2 is paired with R6A:

• Commercial or manufacturing: up to 2.00 FAR from M1-2, or 10,000 sq ft (ZR 43-12, 123-623).
• Community facility: 3.00 FAR from R6A, or 15,000 sq ft (ZR 24-11, 123-621).
• Residential: 3.00 FAR from R6A, or 15,000 sq ft; 3.90 (19,500 sq ft) for qualifying affordable or senior housing (ZR 23-22, 123-622).
• Mixed building: the total is capped by the use with the most floor area, so a 5,000 sq ft ground-floor workshop (1.00 FAR) plus 10,000 sq ft of apartments (2.00 FAR) totals 15,000 sq ft, or 3.00 FAR, with the workshop on a story below the apartments (ZR 123-623, 123-31).
• Height: R6A limits from ZR 23-432 apply, which are a 40 to 65 ft base and 75 ft maximum for standard residences (ZR 123-652).

Parking for homes and community facilities follows the paired residence district, with some M district rules added; MX districts in the Manhattan Core and the Long Island City area use those areas' own parking chapters (ZR 123-70, 123-72).

MX district FAQ

Related pages

• R6A zoning
• R7A zoning
• R6 zoning
• Community facility FAR
• What City of Yes changed