Tools in Development

San Francisco's Community Opportunity to Purchase Act gives qualified nonprofits the first chance to buy buildings of three or more units when they go up for sale. The window is short: a nonprofit has five days to signal interest, and the notice often arrives as a bare broker email. The COPA Triage Tool reads each notice when it lands and assembles the research behind the decision, including ownership, rents, permits and violations, eviction history, and other records that now sit in separate systems. Staff still make the call. We are piloting it with MEDA in the Mission District and designing it to serve the community purchase programs other cities are adopting.

Most low-income renters live in homes with no subsidy: small buildings that existing data systems barely see, and rent-stabilized apartments. Both are most at risk when the property sells. A sale can bring higher rents or pressure on tenants to leave, and a rent-stabilized unit can be re-rented at market rate once it is vacant. Community land trusts often learn a building is at risk only after it lists, while investors pay for data that tells them sooner. The Preservation Knowledge Engine will provide communities with an earlier view: a building-level inventory of housing at risk of losing its affordability, including small buildings and single-family rentals, along with signs that a property may be headed for sale, such as a refinance, a change in the owning entity, tax default, or new permits.

Recent California laws, including SB 684 and SB 1123, have made it easier to build small multifamily buildings on tens of thousands of lots across the state, helping address the shortage of affordable housing. Cities need to know which of their parcels could qualify, and that means checking each one against each law's eligibility rules. The Missing Middle Atlas aims to filter a city's housing element site inventory against these laws and combine the results with Open Rent's parcel and rent data. Planning and housing staff get an interactive map of where missing middle housing could be built, which they can use to plan for it and to share with local partners.