In terms of office rental trends, "rents in Philadelphia are low compared to the cost to build. The amount of office inventory in the city today is the same as it was almost 20 years ago. Despite Cira Center and FMC Tower and Comcast buildings, the reality is there were 15 buildings taken out of service due to residential conversions. To build a new building in the city today, you need rents all in the mid $50s" per-square-foot.