According to the report, refurbishing the buildings' upper levels would help liven up Center City after dark and increase the city's tax base.
The study envisions that the building's owners would spend $35,000 to $45,000 per unit to develop the apartments, then rent them for $500 to $650 a month. The Center City District has identified Regent National Bank as a potential financier of the conversions.
The study, titled ``Turning on the Lights Upstairs,'' was paid for by a $50,000 grant from the Pew Charitable Trusts.
There is currently 1.9 million square feet of vacant office space between Market and Locust streets and Broad and 7th streets, Levy said.
Many of the vacancies were created during a 1980s building boom when tenants vacated buildings east of Broad Street for new buildings on the west side of the city.
Other factors included the recession of the early 1990s, corporate downsizing and the outdated interior design of the buildings.
The study identified 10 buildings as ideal candidates for conversion. Among them: the Delong Building at 12th and Chestnut streets, which has a wig store as well as jewelry and clothing shops on its first floor. The building's six upper floors have been closed since the late 1970s.
Levy said the Center City District hoped to show building owners and developers that changes in the city's building codes make their upper levels easier and less expensive to rehabilitate.
Many older buildings, for example, have wooden water tanks on their roofs that are used to supply water to standpipe systems in the building. The tanks, the study says, could replace the need for a fire pump, saving the building owner up to $50,000.
