A $4.9-million, three-story penthouse on the top of The Westin Book Cadillac Detroit hotel soon will be listed.

A $4.9-million, three-story penthouse on the top of The Westin Book Cadillac Detroit hotel soon will be listed.

Penthouse 2905, which offers more than 5,000 square feet of space, is the largest at the Westin Book Cadillac and the most expensive condo unit ever listed in Detroit. It was the boiler room when the hotel was built in 1924 and now is referred to as a modified mechanical penthouse.

The hotel is located at 1114 Washington Blvd., west of Campus Martius.

Kathleen Yaremchuk bought the penthouse in 2016 and had it renovated over the course of a year. She says she wanted it to retain a 1920s ambiance while offering modern amenities.

“It was kind of the ugly duckling that turned into a swan,” she says.

The penthouse occupies the 29th, 30th, and 31st floors and offers a 360-degree view of the city. It has three bedrooms, each with its own full bathroom and walk-in closet, two powder rooms, a kitchen, a living and dining space, an office, a TV room, a sitting room, and a laundry room.

The boiler room was little more than a cement floor and metal studs when Yaremchuk saw it for the first time. There was no electricity and no water. It was originally scheduled to be renovated in 2008, but the project ended when the economy went south.

“It looked like the workers just packed up and left,” says Jerome Huez, exclusive listing agent of the property and president of Berkshire Hathaway HomeServices The Loft Warehouse in Detroit, adding that they left behind coffee cups and a newspaper from that day.

Yaremchuk says she can see Ford Field, Comerica Park, the Ambassador Bridge, and Belle Isle from the penthouse, as well as cranes from other construction projects. Huez adds that the penthouse is an “island of luxury” that was seemingly dropped on top of the city.

“One by one, these buildings are coming back to life, and there’s new construction going on,” says Yaremchuk.

Integrity Building Group in Detroit served as the builder and architect, and Detroit’s RL Concetti was the interior designer.

The Westin Book Cadillac was the tallest building in Detroit and the tallest hotel in the world when it was built, according to the Detroit Historical Society. The hotel was reopened in 2008 as The Westin Book Cadillac Hotel after the Book-Cadillac Hotel shut down in the 1980s. Now it contains the 400-room hotel and 65 condos, six of which are considered penthouse units, says Huez.

The penthouse is scheduled to officially go on the market April 13. Huez says he has showed it and received inquiries.

More information and photos are available here.