Donahue, AlexThis dissertation focuses on a specific kind of public space—privately owned and mandated for public use and enjoyment. In exchange, the property owner receives bonus floor area or waivers. The arrangement provides a unique dilemma: how can a space provide ideal benefits to the public while recognizing the individual rights associated with a privately owned space? The primary inquiry of this research is to compare Interior Privately Owned Public Spaces (IPOPS) with three other space typologies: Privately Owned, Restricted to Public Space (PORPS), Privately Owned, Publicly Available Space (POPAS), and Urban Street (URBS) to discover how successfully the physical characteristics of IPOPS foster urban public life, focusing on aspects of (a) sociability; (b) inclusion; (c) wayfinding; (d) ownership; (e) well-being; and (f) community. The six themes comprise the Hexa-model for assessing ideal space, a tool the researcher developed for this study. I use the following methods to understand better the connection between the built environment, human use, and interaction: (a) architectural analysis; (b) signage analysis; (c) behavioral observation; and (d) archival analysis. I focus on four case study sites within New York City, each including all four typologies: (a) along Maiden Lane from Water Street to South Street; (b) on East 42nd Street and Park Avenue; (c) around 3rd Avenue and East 49th Street; and (d) along 45th Street between 7th and 8th Avenues. The findings illustrate that while the IPOPS included free-of-charge access to secure, sheltered, and climate-controlled seating, tables, natural light, bathrooms, and plants, there was a relative lack of urban public life. The IPOPS demonstrated a lack of urban public life in limited occupancy and activity when compared to the other spatial typologies and a lack of public space legibility, a generic identity with little sense of place, impromptu closures, a fortress-like aesthetic, and rules that conscribe and exclude the types of uses that are allowed to occur within the space. This research illustrates that in the sample of spaces studied, and compared with other spatial typologies, IPOPS lacked several normative criteria outlined in the Hexa-model. As a consequence, the public is currently not receiving the full benefit of public space as outlined in the agreements made with the city of New York. I recommend that further study be conducted at a larger scale, covering more locations and at various times of day and year to confirm the present study’s findings and promote policy changes to improve the public nature of IPOPS.enDissertationUrban planningPOPSPublic Space