While working on the conversion of the former Cream of Wheat factory in northeast Minneapolis into condominiums, Jon Kainz fell in love with the 65-foot tower that once housed the building's massive water tank. Eventually, that tank was cut into pieces, including a section that was incorporated into the fireplace surround in the building's lobby. In 2005, the raw, but stunning 20-by-20 foot tower space was put up for auction on eBay.

Kainz won the auction. Three years later, the conversion of that space is complete and the unit is for sale. Kainz, an architect who runs a commercial general contracting company, says that with a family too large for the space, he never intended to live in it, but he wanted to see it used to its full potential. And with nine 40-foot-tall windows on all four sides and a 360-degree view, there was plenty of potential.

"You had to imagine what it would look like at that point," he said. "The water tank was still in there and it didn't have any views looking out." He transformed the space into a 1,522-square-foot, one-bedroom condominium with a soaking tub and two private rooftop terraces.

He played up the existing architecture of the concrete-and-brick space by working within massive concrete X-shaped braces that held up the concrete pad that supported the water tank. In the 20-foot-tall space below, there's a living room with an elevated office/den on the mezzanine level. The main level and the master suite all have heated hardwood floors and a dramatic new metal staircase provides access to all three levels.

Built in the early 1920s, the 170,000-square-foot Cream of Wheat building was vacated in 2002 after the company was bought by Kraft and sold to a group of investors including the contractor McGough Cos., which converted it into condominiums.

This isn't the only condo-in-a-tower- conversion in the Twin Cities. When the former Sears warehouse on Lake Street in Minneapolis was converted into the Chicago Lofts condominiums, its prominent tower was carved into four dramatic condo units (including a 14th-floor unit now on the market for $921,900).

Kainz said that the project was a labor of love. Good thing, too. He paid $600,000 for the raw space and put more than $300,000 into its build-out and now has it listed with Barry Berg of Coldwell Banker Burnet for just under $900,000. "It's like a child; you need to let it go and grow on its own," he said.