Why the Most-Quoted Office Occupancy Number Measures Attendance, Not Demand
Every week, a single number gets passed around commercial real estate like a stock quote: the office occupancy reading from Kastle Systems’ Back to Work Barometer. For the week ending September 16, 2026, Kastle put its ten-city average at 56.3%, with Chicago at 57.4%, up 3.4 points from the prior week. Those are useful numbers. They are also routinely misread, and the misreading is starting to cost owners, lenders, and occupiers real money.
The question is no longer whether badge data is valuable. It is whether anyone should still make a leasing, underwriting, or space planning decision on badge data alone. In the Chicagoland office market of late 2026, the answer is increasingly no.
What Badge Swipe Data Actually Measures
Start with methodology. According to Kastle, the Barometer counts only each cardholder’s first building entry per day, averages those figures into a weekly percentage, and compares the result against first-swipe activity during a three-week window in February 2020, which it treats as 100%. Kastle is explicit that the report reflects its own customers in ten metro areas and is not a national statistical sample.
So when Chicago reads 57.4%, it does not mean 57.4% of Chicago office desks were filled. It means unique daily entries at Kastle-secured buildings in the Chicago metro ran at roughly 57% of their February 2020 level. That is an attendance index. It says nothing about how long people stayed, which floor they went to, or whether a tenant needs the square footage it is paying for.
The structural gaps are well documented. Most badge systems record entry but not exit. Tailgating goes uncounted. Visitors and contractors can be mixed in with employees. Density notes that badge data cannot distinguish a salesperson in for a 30-minute meeting from an engineer at a desk for eight hours, and Freespace estimates badge reports can be off by 20% or more. Both companies sell occupancy sensors and have an obvious interest in that conclusion, but the limitations they describe are not really in dispute.
Two Data Sets, Two Different Chicago Stories
The clearest argument for going beyond badges is that the other major attendance data set tells a noticeably different story. The Placer.ai Nationwide Office Building Index tracks visits to roughly 1,300 top-tier office buildings using a mobile device panel and machine-learning estimates. In August 2026, it found national office visits 32.5% below August 2019 but up 6.2% year over year. Chicago outpaced the national year-over-year gain, yet remained roughly 40% or more below its 2019 baseline.
Neither source is wrong. They measure different things, against different baselines, in different buildings. Someone quoting Kastle will describe Chicago as an above-average market running near 57%. Someone quoting Placer.ai will describe it as a laggard still about 40% off pre-pandemic levels. A lender, a tenant rep, and a landlord can each pick the number that supports their position, which is precisely the problem with relying on any single feed.
The Averages Hide the Split That Matters
The most important figures in Kastle’s latest report are not the headline averages. That same week, national occupancy in Class A+ buildings jumped 8.9 points to 79.0%, and the Class A+ peak day reached 95.5%. Across all building classes, the Tuesday peak was 66.5%.
That spread is the office market in miniature. As we outlined in our State of the Chicago Office Market for Q3 2026, Class A product is doing the absorption work while commodity buildings keep losing tenants. A blended 57% tells you almost nothing about a trophy tower that is effectively full on Tuesdays, or about an aging Class B building running at a fraction of the average.
Peak day matters just as much. Tenants do not size space for the weekly average. They size it for Tuesday. A company packed two days a week and nearly empty on Friday has a very different requirement than one with a flat attendance curve, even if both post the same weekly number.
The Suburban Blind Spot
For suburban Chicagoland owners, the problem is more basic. Neither public index isolates suburban buildings, and Kastle does not publicly release data outside its ten Barometer metros. Yet the suburbs are where the flight to quality is producing real rent growth. In Lake County, the I-88 corridor, and the Northwest suburbs, owners are pricing renewals and repositioning buildings without credible attendance data specific to their assets.
What Going Beyond Badge Data Looks Like
Moving past badge swipes does not mean abandoning them. It means treating them as one input in a broader stack:
- Occupancy sensors (thermal, optical, or passive infrared) measure how many people are in a zone, how long they stay, and which rooms actually get used.
- Wi-Fi and network data can approximate dwell time and floor-level presence using infrastructure most buildings already have, with appropriate privacy controls.
- Parking counts are an underrated, inexpensive, asset-specific signal in car-dependent suburban submarkets.
- Location data platforms such as Placer.ai show visit trends at competing buildings, something an owner’s own access system never can.
- Amenity and room booking data shows whether conference centers, fitness rooms, and lounges actually earn their keep.
The goal is to move from attendance to utilization: not who came in, but what space they used, for how long, and on which days. That is what determines how many square feet a tenant renews and what an investor should pay for a rent roll.
What This Means for Owners, Tenants, and Investors
- For owners, building-level utilization data is becoming a leasing tool. A landlord who can show that its amenity floor stays busy or that its parking fills by 9 a.m. on peak days makes a stronger case than one pointing at a metro-wide barometer. It also guides capital spending, a theme we explored in Are Office Employees The New Consumers? and in asking whether owners should make their office buildings pet friendly.
- For tenants facing the current rollover wave, utilization data is leverage. Companies routinely renew the same footprint because nobody measured what they use. A few months of sensor data gathered ahead of a renewal can justify a smaller, better suite, the up-in-quality, down-in-square-footage pattern already showing up across Chicago office leasing.
- For investors and lenders, headline indices are a macro backdrop, not underwriting. The better questions are whether tenants actually use the space, whether peak-day demand supports the rent roll, and which side of the Class A split the building sits on. Assets that fail those tests increasingly end up in office-to-residential conversion analysis rather than leasing plans.
So, Is It Time?
Yes. Badge data did its job during the pandemic, when the only question was whether people were coming back at all. The questions now are how much space, which space, and which buildings, and badge swipes were never built to answer them.
If you are weighing a renewal, repositioning an office asset, or trying to understand real demand in your building, Van Vlissingen and Co.’s brokerage, leasing, and Chicago-based property management teams work with owners and occupiers across Chicagoland’s office submarkets every day and can help you turn raw occupancy numbers into a decision.
Van Vlissingen and Co. has been the Midwest’s oldest commercial real estate brokerage, development, and management firm since 1879, and today is independently ranked the #1 commercial real estate agency in Chicagoland, home to the #1 independently ranked agent, Gordon Lamphere, and the region’s #1 ranked commercial property management team. If you own, manage, or invest in energy-adjacent, mixed-use, or transit-oriented property across Lake County, the North Shore, the Northwest and O’Hare corridors, DuPage and the I-88 corridor, Will County, or southern Wisconsin’s Pleasant Prairie, Kenosha, and Racine markets, contact Van Vlissingen and Co. at 📞 847-634-2300 or 🌐 vvco.com. For a market-wide view of where these dynamics sit today, see our State of the Chicagoland Commercial Real Estate Market for Q3 2026.