72 Pa. Stat. § 4754-3
The following words and phrases when used in this act shall have the meanings given to them in this section unless the context clearly indicates otherwise:
"Improvement." The erection or construction of one or more residential buildings in compliance with laws, ordinances or regulations governing such actions.
"Local taxing authority." A county, city, borough, incorporated town, township, school district or home rule municipality having authority to levy real property taxes.
"Unimproved residential property." Any unimproved real estate owned by an individual, association, corporation or governmental entity located in this Commonwealth, which is or may be zoned, in accordance with the provisions of the act of July 31, 1968 (P.L. 805, No. 247), known as the Pennsylvania Municipalities Planning Code, for residential use.
72 P.S. § 4754-3