Words in italics are defined in Section 12-10 (DEFINITIONS) or, if applicable exclusively to this Chapter, in this Section.

In the flood zone, the provisions of this Chapter are modified by the provisions of Article VI, Chapter 4.

The use of a non-complying building or other structure may be continued, except as otherwise provided in this Chapter.

Repairs, incidental alterations, or structural alterations may be made in a non-complying building or other structure, except that such alterations made in the course of an enlargement shall be subject to the provisions of Section 54-31 (General Provisions).

Except as otherwise provided in this Chapter, a non-complying building or other structure may be enlarged or converted, provided that no enlargement or conversion may be made which would either create a new non-compliance or increase the degree of non-compliance of a building or other structure or any portion thereof. A building that is complying with the applicable bulk regulations may be enlarged or converted, provided that no enlargement or conversion may be made that would create a new non-compliance, except as set forth in Section 54-50 (MODIFICATIONS TO THE PROVISIONS OF THIS CHAPTER), inclusive.

If a non-complying building or other structure is damaged or destroyed by any means, including any demolition as set forth in this Section, to the extent of 75 percent or more of its total floor area, such building may be reconstructed only in accordance with the applicable district bulk regulations, except in the case of a one- or two-family residence, such residence may be reconstructed provided that such reconstruction shall not create a new non-compliance nor increase the pre-existing degree of non-compliance with the applicable bulk regulations. If the extent of such damage or destruction is less than 75 percent, a non-complying building may be reconstructed provided that such reconstruction shall not create a new non-compliance nor increase the pre-existing degree of non-compliance with the applicable bulk regulations.

In addition, the alteration of such existing building resulting in both the removal of more than 75 percent of the floor area and more than 25 percent of the perimeter walls of such existing building, and the replacement of any portion thereof, shall be considered a development for the purposes of the provisions set forth in Section 11-23 (Demolition and Replacement).

In the event that any demolition, damage or destruction of an existing building other than one- or two-family residences produces an unsafe condition requiring a Department of Buildings order or permit for further demolition of floor area to remove or rectify the unsafe condition, and the aggregate floor area demolished, damaged or destroyed including that ordered or permitted by the Department of Buildings constitutes 75 percent or more of the total floor area of such building, then such building may be reconstructed only in accordance with the applicable district bulk regulations.

In any case where the applicant alleges that floor area is an inappropriate measure of the extent of damage or destruction, and elects to substitute reconstruction costs for floor area, an application may be made to the Board of Standards and Appeals to determine the extent of the damage or destruction. Such a building may be reconstructed as provided in Section 54-41 (Permitted Reconstruction), substituting the ratio which the cost of reconstructing the damaged or destroyed portion of such building bears to the cost of reconstructing the entire building, for the percentage of total floor area. In determining reconstruction costs, the cost of land shall be excluded.

Notwithstanding the other provisions of this Chapter, in all districts, a development, enlargement or alteration comprised exclusively of the addition of energy infrastructure equipment, accessory mechanical equipment, or qualifying exterior wall thickness, whether to a building or to an open area of the zoning lot, may create a new non-compliance or increase the degree of non-compliance of a building or other structure, provided that:

1. where locating such equipment in a non-complying open space, yard, rear yard equivalent, or court, as applicable, such equipment shall comply with the applicable height and area restrictions for the respective open area set forth in the applicable underlying district regulations, as applied to the level and size of the non-complying open area;
2. where locating such equipment on the rooftop of a building that is non-complying with respect to height and setback regulations, such equipment shall comply with the height and area regulations for such permitted obstruction set forth in the applicable underlying district regulations, as applied to the level of the rooftop, inclusive of any non-compliance into a required setback area, yard, or other required open area;
3. at any level, all energy infrastructure equipment or accessory mechanical equipment will be enclosed or screened in compliance with the applicable provisions for such permitted obstructions; and
4. where locating qualifying exterior wall thickness into either a non-complying open space, yard, rear yard, or court, or into a non-complying distance between two buildings or a non-complying distance between a building and lot line, or in a location not otherwise permitted by underlying street wall location rules, such additional encroachment of wall thickness shall not exceed the depth permitted by the underlying permitted obstruction regulations.

Notwithstanding the other provisions of this Chapter, in all districts, an enlargement, extension, conversion, change of use or other alteration to a building that furthers the design and construction of facilities for accessibility for individuals with disabilities or furthers building safety by greater conformance with the most recent New York City Construction Codes, may create a new non-compliance or increase the degree of a non-compliance, provided that increases to existing non-compliances, or the creation of new non-compliances, with regard to:

1. maximum floor area ratio shall not exceed ten percent of the existing floor area, or 1,000 square feet, whichever is less;
2. required open space, yards, rear yard equivalents, or courts, as applicable, shall not diminish the size of the required or existing open area, as applicable, by more than 20 percent, and no further encroachment to a non-complying yard shall be closer to a lot line than an existing building or other structure on the zoning lot; and
3. the permitted height and setback of a building or other structure, shall be limited to one story or 15 feet, whichever is less.

Allowances for permitted obstructions may be applied to an existing building, including as modified pursuant to the provisions of this Section.

Notwithstanding the other provisions of this Chapter, in all districts, for buildings where 75 percent or more of the existing floor space is allocated to residential uses, an enlargement, extension, conversion, change of use or other alteration to such building may create a new non-compliance or increase the degree of a non-compliance, provided that:

1. increases to existing non-compliances, or the creation of new non-compliances, with regard to maximum residential floor area ratio shall be limited in size to floor space existing with the volume of a building or other structure on the zoning lot. For multiple dwelling residences, such allowance shall be limited to buildings existing on December 5, 2024;
2. increases to existing non-compliances with regard to required open space, yards, rear yard equivalents, or courts, as applicable, shall not diminish the area of the existing open area by more than 20 percent and no further encroachment to a non-complying yard shall be closer to a lot line than an existing building on the zoning lot; and
3. increases to existing non-compliances, or the creation of new non-compliances, with regard to the permitted height and setback of a building or other structure, or the height of a permitted obstruction, shall be limited to one story or 15 feet, whichever is less.

Allowances for permitted obstructions may be applied to an existing building, including as modified pursuant to the provisions of this Section.