As of December 31, 2022, the company owned interests in 72 properties containing 12.8 million net rentable square feet.

[5] In 2001, the company completed an asset exchange with Prentiss Properties Trust.

[6] In May 2005, the company completed the development of the Cira Centre, designed by César Pelli, next to Philadelphia's 30th Street Station.

[7] In January 2006, the company acquired Prentiss Properties Trust for $3.3 billion.

[8][9] In 2010, the company completed the renovation of Cira Square, a former U.S. post office building that was leased to the General Services Administration for occupancy by the Internal Revenue Service.