2023 Research Prize
A Taxonomy of Vacancy: Are Underutilized Commercial Strips the Answer to San Antonio’s Housing Shortage?

This research challenges San Antonio’s ongoing geographic expansion by identifying and quantifying vacant and underutilized parcels along aging commercial corridors and evaluating their potential to support multifamily infill housing development. The decline of traditional retail and office space, driven by e-commerce and remote work, increases commercial vacancy and creates new opportunities for land reuse. At the same time, shifts in transportation—including shared mobility, automated vehicles, and bus rapid transit—reduce long-term parking demand, further expanding the supply of underutilized land. Repurposing these sites for infill housing supports regional efforts to accommodate an anticipated population increase of more than 600,000 people in Bexar County over the next 25 years, which will require approximately 238,000 new housing units.

This study builds on established research in the urban design and planning literature on the suburban retrofitting of vacant urban land. It integrates data analysis and design research to address a central question: to what extent can San Antonio’s aging commercial corridors accommodate multifamily infill housing at a scale that meets long-term housing demand? The research is structured in two phases. Phase I uses quantitative methods to identify and classify vacant and underutilized parcels along seven major commercial corridors aligned with proposed bus rapid transit routes in the City of San Antonio’s SA Tomorrow Comprehensive Plan and VIA Metropolitan Transit Long Range Plan 2040. Phase II uses architectural design to test infill housing prototypes on prototypical commercial sites, with particular attention to excess surface parking as a primary development opportunity.

Phase I employs GIS-based spatial analysis to inventory parcels within one-mile transects of each corridor, identifying approximately 8,700 vacant parcels and structures totaling more than 7,500 acres. After excluding parcels that are undersized, flood-prone, constrained by ownership, or economically infeasible to redevelop, the analysis identifies 3,938 parcels encompassing roughly 2,720 acres as highly developable. In parallel, the study documents more than 7,000 acres of surface parking associated with commercial uses, revealing a substantial oversupply relative to contemporary parking standards and transit-oriented development norms. Together, these findings demonstrate that the proposed transit corridors possess significant latent capacity to support housing development in already urbanized areas without relying on greenfield expansion.

The research then projects housing capacity across multiple density and parking-reduction scenarios. The analysis indicates that, with reduced parking ratios and medium residential densities of approximately 30–40 units per acre, infill development on vacant and underutilized land along the transit corridors could meet San Antonio’s projected housing demand through 2050 without displacing existing residents or relying on greenfield development.

Phase II translates these findings into eight design prototypes that address normative suburban conditions, including roadside motels, strip malls, big-box stores, and regional malls. This approach emphasizes incremental development, mixed-use programming, and the preservation of existing commercial structures, demonstrating how density can increase without erasing businesses or existing urban fabric. Collectively, the project positions underutilized commercial land as a resource for equitable, transit-oriented growth and offers a transferable framework for cities seeking to address housing shortages by leveraging existing infrastructure and limiting sprawl.

Project Team

Research Team

Ian Caine (UT San Antonio), Wei Zhai (UT Arlington), Huanchun Huang (UT San Antonio), Gabriel Díaz Montemayor (Fayetteville, Arkansas), Esteban López Ochoa (UT San Antonio), Rudy Niño, Jr. (City of San Antonio), and Christine Quattro (Appalachian State University).

Research Assistants

Meesha Afkami, MArch Candidate; Andrea Albarrán Montes, MArch Candidate; Eduardo Lopez, BS Arch Candidate; Sergio Martinez, MArch Candidate; Sajida Noor, MArch Candidate; and Angel Villalobos, MArch Candidate.

Center for Urban and Regional Planning Research, UT San Antonio

Spring 2025 Graduate Studio

Sophia Cruz, Ashmal Irfan, Sarah King, Sergio Martinez, Rodolfo Gerardo Mojica, Sajida Noor, Eduardo Salinas, Santiago Solis Prieto, and Angel Villalobos.

School of Architecture + Planning, UT San Antonio

Acknowledgments

Special thanks to Haley Holmes, San Antonio Public Library; Allison Hu; Trent Tunks, Alamo Architects; Micah Diaz, David Powell, City of San Antonio; Michelangelo Sabatino, UT San Antonio; Iker Gil, SOM Foundation.

Sponsors

Funding provided by the SOM Foundation’s 2023 Research Prize, with additional support from the City of San Antonio, San Antonio Area Foundation, and San Antonio Public Library.

More on this Project

Caine, Ian, and Wei Zhai, “San Antonio Can Avoid Sprawl by Linking Affordable Housing to Rapid Transit.” San Antonio Express-News, November 30, 2025.

Sundeen, Jasper Kenzo, “UT San Antonio Researchers Identify More Than 7k Acres for Housing Development Around Proposed Transit Corridors.” San Antonio Report, December 12, 2025.