San Diego Housing Commission Affordable Housing Preservation Study

Recognizing the opportunity the City has to invest in its existing housing stock to preserve affordability, the San Diego Housing Commission (SDHC) engaged HR&A and National Housing Trust (NHT) to create the Affordable Housing Preservation Study — a robust inventory and projections of San Diego’s existing affordable housing and a policy framework designed to preserve affordability.

With government subsidies to preserve existing affordable housing set to expire in the near future, SDHC needed our help understanding what naturally-affordable housing exists throughout the city in order to identify properties that could benefit from those programs. In response, HR&A developed a parcel-level inventory of all available subsidized and naturally affordable multifamily housing in San Diego.  

To create this detailed inventory, HR&A developed a regression algorithm  — using indicators like location, building age, size, and school district — that estimated the likelihood that parcel included naturally-affordable units. Based on this analysis, we developed typologies for the most common kinds of multifamily buildings with the most naturally-affordable units and mapped the city’s NOAH inventory. We then developed financial analyses for each of the typologies to estimate the subsidy required to preserve each unit. 

The typology definitions informed the development of targeted policy recommendations for preservation, developed in collaboration with the National Housing Trust. The recommendation framework detailed policy tools, capacity-building, and financing sources to support preservation activities, as well as a review of nationwide best practices for preservation in comparable jurisdictions. SDHC will use these recommendations to form the basis of their preservation strategy for their general plan update and to guide policy in the coming year.