Chicago's office market just quietly defused one of its biggest headaches: an overstuffed pile of sublease space. The share of offices being marketed for sublease has slipped in recent data, giving landlords a bit more room to push asking rents. After a long run of elevated sublet listings, the shift suggests the market is inching away from pure survival mode and toward something that looks more like a cautious recovery.
According to CoStar, total available office space across the Chicago market stands at about 95.6 million square feet and roughly 8 percent of that inventory is being marketed as sublease. CoStar notes that Chicago’s sublease share sits below the national average of about 10.9 percent and frames the tightening as removing a key headwind to future rent growth. The story was published March 12, 2026, by CoStar Analytics reporter Adrian Brizuela.
Sublease Blocks Keep Shrinking
Brokerage data backs up the analytics. Transwestern's March 2025 Chicago CBD sublease report showed about 5.65 million square feet of CBD subleases, down from a December 2023 peak above 8.26 million, marking multiple consecutive quarters of decline. Transwestern's report documents large blocks being removed either because subletters were found or because those spaces reverted to direct vacant listings when leases expired. Those mechanics help explain why the share of total market inventory counted as sublease has fallen even while overall vacancy remains elevated.
Flight To Quality Reshapes Demand
Leasing activity has clustered in higher quality buildings, including the West Loop, Fulton Market and newer Class A stock, a pattern industry coverage calls a "flight to quality." Reporting by Commercial Observer and local brokers shows that newer, amenity rich space is capturing most leasing, leaving older assets and some suburban corridors behind. That split market helps explain how rents can climb for top tier space even as the broader market still carries heavy vacancy.
Suburbs And Conversions Complicate The Picture
The suburban story is different. Cushman & Wakefield reports suburban sublease availability was about 1.3 million square feet at year-end 2025, down roughly 26 percent year-over-year, while Class A asking rents in inner suburban pockets held firm. Cushman warns that underused suburban campuses are increasingly candidates for conversion to other uses, a trend that would tighten traditional office supply even more. Those dynamics mean the market's improvement is uneven and hinges heavily on building quality and location.
What To Watch Next
If sublease supply keeps sliding, landlords will have clearer leverage to push rents and to market renovated space. Still, Chicago's overall occupancy remains below pre pandemic levels and the recovery is far from uniform. Local reporting shows office "busyness" at roughly 56.6 percent of pre pandemic activity as of November 2024, underscoring that demand still has room to recover, per WBEZ. For clues on whether this is a lasting rebound or just a breather, watch upcoming large expirations, big sublease blocks and quarterly leasing tallies.
