A $5 million shell underwrites a $113 million conversion

The 25-story office tower at 500 North Michigan Avenue sold last August for $5 million, while the 21,565 square feet of retail at its base sold in April for $41 million. A downtown Chicago high-rise went for roughly an eighth of its street-level storefront space, and that ratio is doing more underwriting work than the Magnificent Mile address.

Commonwealth Development Partners and Triangle Capital Group have now closed $113 million to convert the empty building into 384 mixed-income apartments, splitting the package into $71.5 million of non-recourse construction debt from Santander Bank and $41.5 million of joint venture equity from Washington Capital Management; JLL Capital Markets' Chris Knight, Ryan Planek and Annie Thomas arranged the transaction, which Crain's Chicago Business first reported.

Ground was broken in May 2026 and completion is expected in March 2028, so call it 22 months of construction, close to the 21-month exposure in the Affinius Lexington construction loan, before the first rent check. Add the $5 million acquisition to the $113 million of financing and the full capitalization lands near $118 million across 384 units, roughly $307,000 a unit spread over more than 250,000 square feet of rentable apartment space—a budget built on a shell price rather than on the value of the office it replaces.

Washington Capital Management came to the building before it wrote the equity check, buying the 21,565 square feet of ground-floor retail in April for $41 million from Commonwealth and funding the $41.5 million joint venture months later; separate in the reporting, the two transactions put one manager roughly $82.5 million into a single address. Robin Dean called the two sponsors “an experienced sponsorship team” and the building an “irreplaceable location.”

The $71.5 million Santander facility spreads across 384 units at about $186,000 a unit, close to the $188,000 a unit on a stabilized Harrison, N.J. apartment loan. Construction debt that prices near stabilized multifamily debt rests on the equity beneath it and the shell above; the historic-credit pieces have yet to land.

The 384 units split 320 market-rate and 64 affordable, and the 1960s architecture stays intact, which does double duty: the project aims to secure Federal Historic Tax Credits and to draw benefits from the Illinois Affordable Housing Special Assessment Program, with the affordable set-aside the likely qualification for the state piece. A sponsor pursuing historic credits rather than holding them is underwriting a recovery in two parts, and only one of them is rent.

What the conversion is really buying is the location: the tower sits in the Loop's Streeterville neighborhood near Northwestern Memorial Hospital, Lurie Children's Hospital and the University of Chicago Booth School of Business, with an amenity set—rooftop pool, fitness center, coworking space, theater, ground-floor retail, 60 parking spaces—that is standard for a downtown lease-up. Demand for these units likely comes from the hospital and university payrolls, not from the corporate tenants the building was designed to hold.

Delivery is scheduled for March 2028, and the calendar carries the thesis: as this publication has argued, the next multifamily winners are the capital that can underwrite the 2028-29 supply gap today, and a conversion that breaks ground in 2026 and delivers at the front edge of that window is that trade in its plainest form. Commonwealth's Matthew Faris made the rent case directly, describing a world-class address in the city's “Eds and Meds” neighborhood and citing Chicago multifamily assets up 6.5 percent year over year.

The risk sits in the finish: a non-recourse construction loan covering 63 percent of the stack, with equity under it and no rent roll until 2028, expects the historic-credit application to succeed, since the sponsor is aiming at those credits rather than holding an award. What keeps the structure coherent is the basis: an owner that paid $5 million for a shell can carry a slower lease-up than one that paid office prices, and that gap is what lets a bank write non-recourse money on a building no one wanted. Banks have written construction loans against equity and a completion calendar for decades, and the cushion here—$41.5 million under a $71.5 million facility—is the ordinary kind. The input is the trade worth pricing: a conversion that resolves a dead office by changing its use rather than rolling its debt forward, a route beside the extensions and preferred-equity rescues that define the refinancing wall. If the historic credits land and the units lease at the front of the supply gap, 500 North Michigan becomes the template for the next empty Loop tower; if the credits slip, the $5 million basis is what buys the sponsor time.