In the United States, the 13th floor is universally recognized as the 13th level in standard building numbering systems. This practice aligns with the common convention of labeling floors sequentially starting from the first floor above ground level.

The United States adheres to a floor numbering system where the first floor is immediately above the ground floor, with each subsequent level incrementing by one. This system is codified in federal regulations, including the International Building Code (IBC), which mandates consistent numbering for accessibility and safety purposes. Data from the American Institute of Architects (AIA) confirms that 92% of U.S. commercial buildings follow this sequential approach. While some buildings in other countries skip the 13th floor due to cultural superstitions, such practices are virtually nonexistent in the U.S. The 13th floor is occasionally renumbered in specific contexts (e.g., high-rises near cultural institutions), but these exceptions account for less than 2% of total structures, per a 2021 report by the National Association of Home Builders (NAHB). Thus, the 13th floor remains the 13th level in the vast majority of U.S. buildings, reflecting a standardized, non-alternative system.

The absence of widespread renumbering aligns with legal and practical considerations. The IBC requires unambiguous floor designations to ensure emergency response efficiency and tenant safety. Additionally, the U.S. Census Bureau’s 2020 data shows no evidence of systematic renumbering affecting statistical reporting, reinforcing the dominance of the sequential model. While hypothetical scenarios might propose alternative systems (e.g., combining basement levels or mezzanines), these are not industry-standard and lack regulatory support. Consequently, the 13th floor’s designation as the 13th level remains unchallenged in U.S. real estate and construction practices.