N.Y.C. Admin. Code § 27-566: § 27-566 Floor live loads.

The uniform live load to be used for design shall be the basic value established in reference standard RS 9-2 multiplied by the percentages given in subdivisions (a) through (d) of this section.

(a) Except as provided in subdivisions (b), (c), and (d), the percentages in table 9-1 shall apply. Contributory areas shall be computed in accordance with section 27-567 of this article.

(b) No live load reduction shall be permitted for the following: members and connections (other than columns, piers, and walls) supporting floor areas used for storage (including warehouses, library stacks, and record storage); areas used for parking of vehicles; and areas used as place of assembly, for manufacturing, and for retail or wholesale sales. For columns, piers, and walls supporting such floor areas the maximum live load reduction shall be twenty per cent.

(c) No live load reduction shall be permitted for calculating shear stresses at the heads of column in flat slab or flat plate construction.

(d) In lieu of the percentages given in table 9-1, the live load reductions for columns, piers and walls may be taken as fifteen per cent of the live load on the top floor, increased successively at the rate of five per cent on each successive lower floor, with a maximum reduction of fifty per cent; and for girders supporting two hundred square feet or more of floor area, the live load reduction may be taken as fifteen per cent. The limitations of subdivisions (b), (c) and (d) of this section shall apply.

TABLE 9-1 Percentage of Live Load*

Contributory Area

Ratio of Live Load to Dead Load*

0.625 or less

1

2 or More

149 or less

100

100

100

150-299

80

85

85

300-449

60

70

75

450-599

50

60

70

600 or more

40

55

65

Note for Table 9-1: * For intermediate values of live load/dead load, the applicable percentages of live load may be interpolated.