N.Y.C. Admin. Code § 27-647: § 27-647 Special glasses.

For types of glass other than single annealed sheet and plate glass, allowable maximum areas may be determined by multiplying values in table 10-7 by the appropriate multiplying factor listed in table 10-8.

TABLE 10-8 Multiplying Factors for Various Types of Glass

Glass Type

Multiplying Factor

Full tempered

4.0

Heat strengthened

2.0

Factory-fabricated double glazing

*1.5*

Laminated

0.6

Wired

0.5

Sandblasted or etched

0.4

* For asymmetrical units base strength on thinner lite.