As an existing 2 story home with a neighboring 3 story house, we were able to avoid the 8' setback on this big undertaking of a project which consisted of digging down 3' in the basement followed by underpinning all the way around, a full interior demolition and renovation, plus a 3rd story addition with roof top deck.  Because of the percentage of structural demolition that we did, we were required to get new construction permits that dictated we install a fire sprinkler system.  This needed a new water service from the street!  Digging up the sidewalk and having to engage PGW and PECO to reroute the underground utilities was the biggest challenge of the entire project, but all worth it in the end.