N.Y. Multiple Dwelling Law § 211: Height and bulk

§ 211. Height and bulk. 1. No tenement shall be increased in height so

that its height shall exceed by more than one-half the width of the

widest street upon which it stands. Except as otherwise provided in

subdivision four of this section, no non-fireproof tenement shall be

increased in height so that it shall exceed five stories, except that

any tenement may be increased to any height permitted for multiple

dwellings erected after April eighteenth, nineteen hundred twenty-nine,

if such tenement conforms to the provisions of this chapter governing

like multiple dwellings erected after such date.

2. If there are bulkheads, superstructures or penthouses exceeding ten

feet in height or exceeding in aggregate area ten per centum of the area

of the roof, the measurement of height shall be taken to the top of such

bulkhead, superstructure or penthouse, except that this shall not apply

to elevator enclosures not exceeding twenty-three feet in height used

solely for elevator purposes, nor to open pergolas or similar open

ornamental treatment of roof-gardens or playgrounds.

3. In a fireproof tenement house in which one or more passenger

elevators are operated, penthouses may be erected on the main roof.

Such penthouses shall be set back at least five feet from the front

walls and ten feet from the rear walls of the dwelling and at least

three feet from any court wall. Such penthouses shall have a clear

inside height of not less than nine feet from finished floor to finished

ceiling, and shall not exceed twelve feet in height from the high point

of the main roof to the highest point of the penthouse roof. Such

penthouses shall not be deemed to affect the measurement of height of

the dwelling. All such penthouses shall be entirely fireproof except

that windows shall not be required to be glazed with wire glass.

4. Any non-fireproof old-law tenement five stories in height may be

increased in number of stories to six provided that such increase in

number of stories does not result in an increase in the height of the

roof beams above the curb level. In any tenement so altered, the first

floor above the lowest cellar, or, if there be no cellar, above the

basement or other lowest story, shall be fireproof. Any yard or court of

such altered tenement shall not be less in any dimension than the

minimum dimensions prescribed in section twenty-six.