Such transformations are part of a national trend. CBDs across the country have garnered a great amount of much-deserved attention as companies and new residents and flood into urban cores, but well-located class A properties in the suburbs have also been standout performers.

“The suburban properties which do the best are typically larger assets that are well-capitalized and amenitized,” Klein says. Essentially, a select group of suburban landlords have been able to create office complexes that provide amenities similar to those found in downtown trophy buildings, and both tenants and investors see the value.

Walton Street ran the sale of Continental towers, Klein adds, while GlenStar provided guidance to investors that came in to look over the property. At some point in the process, Rubenstein asked if GlenStar was willing to form a partnership. What made the idea work for GlenStar was that the two firms agreed on how the capital plan would work going forward. And for Rubenstein, the property was a perfect fit.

“This is what they target,” Klein says. “They're looking to buy top-quality assets in high-performing submarkets, assets that are considered market leaders.” In 2016, for example, the company bought Parkland Crossing, a 1.2 million square foot office park in suburban Indianapolis, for $162.9 million from developer Duke Realty Corp.

Continental Towers does have an upcoming vacancy. Komatsu America Corp. will leave roughly 100,000 square feet and move its headquarters to Triangle Plaza in the O'Hare submarket. Klein says that gives the new ownership a three-year runway to attract another top-quality tenant to Rolling Meadows. “For us, that's an opportunity.”