September 20, 2021
San Diego Housing Commission Study Finds Less Than 1 Percent of Housing Units in San Diego are Vacant Long-Term
SAN DIEGO, CA — A San Diego Housing Commission (SDHC) study to analyze vacancies among homes in the City of San Diego as a potential factor in the city’s housing crisis identified less than 1 percent of residential housing units were vacant for at least six consecutive months at some point during a five-year period before the COVID-19 pandemic.
“This study provides important data—based on best practices from similar studies in other communities—to inform discussions and decision making as the City of San Diego continues to address housing affordability challenges,” SDHC President & CEO Richard C. Gentry said. “I thank the Board of Commissioners for their leadership on this issue.”
To help determine the extent to which homes are vacant in San Diego, the SDHC Board of Commissioners directed SDHC staff to commence a study to identify units vacant for six months or longer.
SDHC staff worked with SDG&E and the City of San Diego’s Public Utilities Department to obtain anonymous data about utility and water usage as indicators of potential vacancy. SDHC then contracted with Circulate San Diego and Evari GIS Consulting to analyze the data.
Residential water and electricity data were used because nearly all occupied residential units use these utilities, which are provided citywide and are billed regularly.
A six-month term represents a significant period for a unit to be unoccupied and helps to avoid periods that could reflect low-energy use but not vacancy, such as residential turnover and extended vacations.
SDHC obtained a dataset of 468,352 unique SDG&E premises IDs with utility usage for five calendar years (2015 – 2019). This produced 86 million anonymous records of residential utility usage.
A housing unit was determined to be “unoccupied” if the utility usage for a particular month fell below three standard deviations of the unit’s respective 60-month average. For comparison, the study also analyzed the number of units for which utility usage was below two standard deviations from the 60-month average. Based on monthly utility usage, between 1,500 units (0.32 percent) and 3,700 units (0.79 percent) could reasonably be considered potentially vacant for six months or more in the City of San Diego in the period between 2015 and 2019.
SDHC also obtained City Public Utilities Department data for 33,848 residential accounts that had active water meters but no contract accounts at some point between 2015 and 2019. This was a subset of 253,324 individual metered accounts in the City. For this study, a residential record was considered to be potentially vacant if it had no active metering for six consecutive months or more. The study identified 2,138 potentially vacant units or approximately 0.85 percent of the 252,324 individual metered accounts in the City.
The study includes a list of similar vacancy studies, and an overview of the methodologies they used.
Vice President of Communications
San Diego Housing Commission