Chicago Loses a Two-to-Six-Flat Every Day: The Quiet Disappearance of the City’s Housing Ladder
The Assessor's rolls show 7,914 small apartment buildings leaving Chicago's two-to-six-flat stock since 2006, about one a day, while prices rose 62 percent and more than one buyer in four became a corporate entity. The city's housing ladder, measured.
The two-to-six-flat is about as Chicago as a building gets: brick, often a century old, a family on each floor, and very often an owner living behind one of the doorbells. For a hundred years it did quiet double duty as a huge share of the city’s lower-cost rental housing and a dependable wealth ladder, the building you bought to live in that paid for itself. This piece is about three numbers that describe what is happening to it: the stock is shrinking, the price has left its old owners’ reach, and a rising share of the buyers are not families at all.
7,914
two-to-six-flat buildings gone from the rolls since 2006
≈1 a day
the pace of loss, held steady for twenty years
+62%
median flats sale price since 2019
27%
of 2024-25 flats purchases went to corporate entities
Chicago loses about one flat building a day
The Cook County Assessor’s rolls carried 127,818 two-to-six-unit apartment buildings in Chicago in 2006 and 119,904 in 2026. That is 7,914 buildings that left the category in twenty years, demolished, converted to condos, merged back into single homes, or reclassified, a net loss of about 1.1 per day that has run at nearly the same pace through the crash, the recovery, and the pandemic. We verified the series against the county’s archived parcel files; the older and current records agree to within a twentieth of a percent.
Where do they go? The permit file cannot isolate flats, but citywide demolition permits of all building types fell, from 2,225 in 2018–19 to 1,296 in 2024–25, so an accelerating wrecking ball is not the obvious explanation. A flat also leaves the class when it is converted: split into condos, or deconverted into one large house, a path documented on the North Side, where the land under a two-flat can be worth more as one home than as three. Our records show the subtraction precisely but not the split between those paths; that decomposition is a follow-up we intend to run. What the total already establishes is that this stock, a major share of what housing researchers call naturally occurring affordable housing, has been smaller at every measurement since 2006, through every administration and market cycle in the window.
The price left the family buyer behind
Tap any area for its numbers. Left of the line is 2019; right is 2025.
In 2019 the median Chicago flats sale was $274,500. In 2025 it was $445,000, up 62 percent, the fastest of any home type in the city, as our recorded-sales analysis showed. Drag the divider and the change is geographic as well as steep: the South and West Side areas that were the lightest blues in 2019 darken sharply by 2025, Woodlawn from $190,000 to $512,000, North Lawndale from $175,000 to $375,000, West Englewood from $63,000 to $225,000. The old arithmetic, where a schoolteacher’s salary plus two rents could carry a mortgage on a building like this, stops working somewhere well below these prices.
Who is buying the buildings
Across 2024–25, 27 percent of Chicago flats purchases went to LLCs, corporations, and similar entities, up from 24 percent in 2018–19 and the highest share of any home type. The geography splits into two different corporate stories. On the South Side the shares have been high for years: Greater Grand Crossing at 36 percent, South Shore at 37, Roseland rising to 37. On the North Side the shares are newer and steeper: half of Lincoln Park’s flats purchases in 2024–25 were corporate, and North Center jumped from 25 to 45 percent in six years, in the same neighborhoods where the median house now clears $1.5 million and a two-flat lot is worth more as one home. The deeds do not state intent, but the two patterns sit at the two ends of the building’s life cycle: bought for the rents, or bought for the land.
DePaul’s Institute for Housing Studies documented the mechanism a decade ago along the 606, where rising land values eroded the two-to-four-flat stock fastest precisely because those buildings were the cheap ones. The numbers above suggest that mechanism is no longer a trail-adjacent curiosity. It is citywide.
Why one building type carries this much weight
Flats hold a large share of what researchers call naturally occurring affordable housing: units that are cheaper because the buildings are old, not because any program requires it. A building that converts typically takes its rental units off the market for good. Flats are also where first-generation wealth started for many Chicago families, the building that let a tenant become a landlord without becoming a company. A market where the entry asset costs $445,000 and one buyer in four is an entity is a market where that path narrows. Whether the city’s renter-protection fight, PRO versus FAIR, reaches any of this is worth watching precisely because most of these units answer to no affordability rule at all.
How we measured this
Stock: count of Assessor class-211 parcels (apartment buildings of two to six units) in Chicago’s eight townships, from the Parcel Universe (nj4t-kc8j) at four-year vintages 2006–2026, cross-checked against the archived universe (tx2p-k2g9; agreement within 0.05 percent). A parcel leaves the class through demolition, condo conversion, deconversion, or reclassification; the count nets new construction against all losses.
Prices and buyers: arms-length recorded sales of class-211 buildings from the Parcel Sales file (wvhk-k5uv), 2018 through May 28, 2026; buyer names classified as in our gentrification report, with trusts and banks excluded from the corporate share. Area figures suppressed under 40 sales per period.
Demolitions: city wrecking/demolition permits (ydr8-5enu), all building types, pooled 2018–19 vs. 2024–25; the file does not identify flats specifically.
