John Buck II

Buck’s fingerprints can be found on some of the city’s largest office developments.

As founder and CEO of the real estate development firm he launched in 1981, Buck has focused on large-scale office and mixed-use development in urban cores, often partnering with institutional capital. Some of his most prominent projects are 155 North Wacker Drive and 151 North Franklin Street, a 35-story office tower completed in 2018.

The Franklin Street building was well-received architecturally and delivered into a strong market for leasing in 2018, landing Facebook as a tenant right before the pandemic flattened the office market.

More recently, Buck has been managing refinancing pressure across parts of the portfolio. In early 2025, the company secured a loan modification on 33 North LaSalle that reflected a diminished property value, punctuating the broader challenges facing Loop landlords as leasing and valuations bounce back from the pandemic.

Buck has also continued to position for a rebound. In 2023, his firm paid $53 million for land at 655 West Madison Street in the West Loop and reworked plans for the site into a two-tower office development. But caution embedded in large-scale office development amid tight financing and uneven tenant demand has stalled the start of construction.

The firm has also pursued office-to-residential conversion opportunities and repositioning plays as downtown office vacancy rose to nearly 30 percent. Those efforts reflect Buck’s willingness to adapt, though they also highlight the difficulty of redeploying capital once grounded in office toward reuse as financing constricts.