Which of the following is NOT a standard in building codes?

The choice identifying ISO as not a standard in building codes is correct given the context of building regulations within the United States. While ISO, the International Organization for Standardization, develops global standards across a wide range of industries, it does not specifically create building codes that are directly applied to construction and safety regulations in the U.S.

In contrast, UL (Underwriters Laboratories) focuses on safety standards and certifications for various products, including those used in construction. ANSI (American National Standards Institute) oversees the development of American national standards across numerous industries, including construction and building safety. NFPA (National Fire Protection Association) is well-known for its fire safety codes and standards that directly influence building design and construction practices.

Therefore, ISO, while important in the broader context of international standards, is not regarded specifically as a standard source for building codes within the United States, which is why it stands out in this assessment.