Philadelphia overhauled its system in 2014 when it began assessing properties at 100 percent of the market value — or the amount at which a home would sell on the open market. Under the so-called “Actual Value Initiative" (AVI), the city said every property in the city would be reassessed every year. The 2019 hikes in values for homeowners came in part, officials said, because OPA had not reassessed all residential properties in a few years.