Conversions in buildings or portions thereof, existing on December 31, 1990, shall be subject to the provisions of this Chapter. For the purposes of this Chapter, conversion shall mean the change of non-residential floor area to residences of any type, joint living-work quarters for artists or community facilities with sleeping accommodations. However, non-profit institutions with sleeping accommodations shall be limited to those with Class A occupancy as defined in the New York State Multiple Dwelling Law.

Conversions shall also include the conversion of existing floor space used for mechanical equipment and not counted as floor area to residences or joint living-work quarters for artists or community facilities with sleeping accommodations.

The provisions of this Chapter shall apply in any Special Mixed Use District to buildings or portions thereof, existing on to December 10, 1997.

All conversions to residences or community facilities with sleeping accommodations shall be permitted only in districts where residential use is allowed by the district regulations, or in those Manufacturing Districts where residential use is allowed pursuant to this Chapter or by authorization or special permit. All conversions to joint living-work quarters for artists shall be permitted only in districts where such use is allowed by the district regulations.

However, conversions that meet all the requirements for residential developments or community facilities with sleeping accommodations developments pursuant to Article II (Residence District Regulations) and are located in R1, R2, R3, R4, R5, R6, R7, R8, R9, R10, R11, R12, C1, C2, C3, C4, C5 or C6 Districts are exempt from the provisions of this Chapter. Except as modified by the express provisions of this Chapter, the regulations of the applicable zoning districts remain in effect.

Developments or enlargements shall be in accordance with the applicable requirements of Article II and Article III, except as provided by authorization pursuant to Section 15-21 (Enlargements of Converted Buildings).

Except as specifically set forth in Section 15-024 (Special bulk regulations for certain pre-existing dwelling units and joint living-work quarters for artists), the provisions of this Chapter are not applicable in M1-5B Districts.

The conversion of floor area within transient hotels to residences or community facility uses with sleeping accommodations pursuant to the provisions of this Chapter shall be limited to those buildings eligible for conversion pursuant to the rules of this Chapter in effect prior to December 5, 2024.