Joseph Santoro, who owns a landscaping and snowplowing business, plans to build a $650,000, 8,185-square-foot office and warehouse building on a vacant 37,287-square-foot lot in the Menomonee Valley at 1205 W. Mt. Vernon Ave., Milwaukee. According to documents filed with the city, Santoro has eight full-time employees and plans to add 20 new jobs within the next three months. Santoro is buying the property from the City of Milwaukee Redevelopment Authority for $34,262. The redevelopment authority has owned the property since 1978.