The DC Tenant Opportunity to Purchase Act requires landlords to notify tenants in advance of a property sale, so that tenants can exercise the right of first refusal to make an offer to purchase. Although the primary use case for tracking TOPA notice issuance is to enable affordable housing advocates to ensure that affected property owners receive the support they might need to intercede with the property owner before a subsidized property is lost due to a sale, data regarding TOPA notices can also be a potentially useful indicator of affordable housing inventory loss rates in a given neighborhood or zone more generally.
Urban Institute has spreadsheet versions of the data obtained directly from the DC Department of Housing and Community Development (DHCD), which is provided to Urban Institute on a regular basis. The data currently included in the Housing Insights project spans the period 2015-2017.