NPDF - The Cornerstone, Philadelphia, PA, 19143. Bedrooms: 0-3. Neighborhood Preservation and Development Fund (N.P.D.F) welcomes you to a lifestyle of comfort and convenience in the University City section of West Philadelphia. The University City area is a great place to live work eat and go to school. N.P.D.F. operates over 400 apartments in 20 locations. You can walk or bike to school at nearby University of Pennsylvania or Drexel University or take a 15 minute bus ride to work in Center City Philadelphia. The Cornerstone is an historic building that combines original architectural features with modern amenities such as kitchens with range refrigerator and garbage disposal carpeting or hardwood floors on-site laundry facilities controlled access entry public transportation at your door 24-hour emergency maintenance and professional management.