CHICAGO—After several years of tightening, the vacancy rates in some of Chicago's downtown submarkets have started to increase, largely due to the recent opening of several class A towers. The movement of so many tenants into these new trophy properties has opened up holes in other buildings, and many observers feel that the tipping point in Chicago office fundamentals that has been favoring landlords is approaching. In other words, events are unfolding as predicted.

“This is what happens in markets when new space is delivered,” Jeff Dowdell, senior vice president, Transwestern, tells GlobeSt.com.

Chicagoland's overall office vacancy decreased 10 bps to 16.8% with a total negative net absorption of 62,832 square feet, according to a new mid-year report from Transwestern. The CBD's net absorption in the second quarter was only slightly positive at 16,006 square feet. But there is currently 4.1 million square feet of sublease space available in downtown Chicago with 1.63 million square feet vacant and available for immediate occupancy. Many of these openings are class A and B spaces with long lease terms remaining, and these “leave behind” spaces are a growing concern for CBD landlords.