It's not too much of a stretch, since Signature is also the manager of the Bridgewater Place office building next door. Both Signature and Robert Grooters Development (RGD), the developer of both River House and Bridgewater, are tenants in the 17-story office tower.

The 207 units in the new condo tower, with an address set as 335 Bridge Street, are already 70% sold, says Dan Wert with RGD. He says while the condos started out four years ago with a low price in the high-$100,000s, going up to $1.5 million, the average price was about $400,000. The remaining inventory average would be about $321,000, he says. The condo tower will be attached to the 400,000-sf office building, and will share a 1,392-space parking deck. "There's going to be two spaces for every resident that are either covered or enclosed," Wert says. Though RGD built Bridgewater in 1993, the company no longer owns the facility.

With the state of the economy, especially in Michigan, it's difficult to see why RGD decided to build River House. Plus, the housing market has been terrible in Michigan, in a state where condos never really took off in the first place. "It's a question we mulled over for a few years," Wert tells GlobeSt.com.