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.

There's a few reasons the company ultimately decided to pull the trigger, he says. First of all, the West Michigan economy is not as tied to the struggling automotive industry as is Detroit. Also, one industry that has grown in the area is the medical field. "There's a billion dollars of new development going on within a mile or so of our project, and much of it is in the medical industry," Wert says. "Michigan State University has recently relocated its medical school here, and we have a few cancer centers opening up nearby, as well as a children's hospital. We're seeing over the next five years an estimated 2,000 to 5,000 new jobs within a quarter mile of our project."

Another reason, he says, is that Grand Rapids has great benefactors, with four billionaires, including Amway's DeVos family, who regularly contribute to the community and the Downtown infrastructure. "Grand Rapids is not just a flash-in-the-pan city," Wert says. "I wouldn't be surprised to see this growth trend continue for the next 15 to 20 years."