Hedge-fund billionaire Ken Griffin’s four-floor penthouse measures 25,000 square feet. With a purchase cost of nearly $59 million, the residence’s tally is still racking up; it may not be finished before the Citadel founder has spent an additional $20 million on its construction. Griffin purchased each of the four floors piecemeal in his mission to build the ideal Chicago residence. The sales were completed in November of last year.

The building—No. 9 Walton—is located on the Gold Coast, just north of downtown. The purchases in the building set a record for the city, and the property now represents the most expensive residence in Chicago. Griffin’s floors extend from 35 through 38. The developer contracted for the renovation extended the total living space by 7,000 square feet, adding a private indoor pool to the layout.

The finished home will feature very high ceilings, which may be read as a metaphor. Photos of the actual interior are not currently available, but the photo suite below gives an indication of the spirit of the building itself, and the units as they were sold to Mr. Griffin.

Griffin’s other sky-high residential holdings include a substantial residence directly across the street from this latest purchase: a full floor of Chicago’s old Waldorf Astoria Hotel, which has been a condo-complex in construction since it was purchased by an investment group in 2015. The Chicago Landmarks Preservation Commission has designated portions of the historic building as untouchable.