The architect Kent Bray has designed enough buildings to no longer be surprised when they rise from drawings to finished projects.

But something about Missoula's new First Interstate Bank, which opens downtown on Tuesday, hadn't fully caught his eye.

"I can usually sort of see what it's going to be like, but when I looked out toward the pedestrian area on the river side of the building, I was just surprised and pleased to see how much better it worked with the new building," said Bray, a principal at CTA Architects and Engineers. "I hadn't really seen that coming."

The same might be said of how the new building works downtown, particularly when compared to the dated structure it replaces.

"I think the building works with the history of downtown, but also represents something new," said project manager Dan McGee, who previously worked for CTA and now works for McKinstry. "We definitely wanted it to reflect what's really good about downtown Missoula."

And reflect it does. The Wilma and Millennium buildings as well as the surrounding landscape are constantly mirrored in the new building's windows, and the sight is never the same.

"We've already got customers sending us pictures from all different times of day," said First Interstate's Sue Larew.

The building opens Tuesday morning, about 20 months after construction started in February 2008.

"I think from the banking perspective, it's just going to be nice to all be back together again," said Dave Olson, senior vice president. "We've had our employees and our customers scattered all over during the past two years."

On Tuesday, they'll enter an elegant, understated building that respects history while pushing into the future in terms of energy efficiency. The bank is seeking Leadership for Energy and Environmental Design certification for the 118,000-square-foot building.

Designed by CTA and built by Gordon Construction, the building features low-flow plumbing, rainwater catchment, low-e insulated windows and a wide variety of nontoxic and recycled materials. Lights turn off when no one's around and groundwater will be used to keep the bank cool during warm months.

"It used to be, five years ago, it was hard to even buy the materials we used here, but now they're much more widely available," said Kevin Gordon of Gordon Construction. "It's nice to be able to work with this stuff."

And it's not just the new building making use of recycled materials. About 97 percent of the old bank was itself recycled, Gordon said, and most of the construction waste from the new building was also recycled.

"That building was mostly concrete and steel, so we were able to get the steel out to Pacific and the concrete all gets crushed up into aggregate to make new concrete," Gordon said.

First Interstate will occupy three floors of the building, while Galusha Higgins and Galusha will take the third floor and GT Solar International will lease the fourth floor.

"The fifth floor we're going to lease out, but haven't really even started marketing it yet," Olson said. "There's also a cafe space on the first floor that we'll look to lease."

First Interstate considered building a new bank outside the downtown area, but eventually opted to remain on the corner of Front Street and Higgins Avenue.

In fact, a bank has occupied that corner since the late 1800s, and the door to the vault in the original bank still has a place in the new facility.

"We're excited to be able to serve all our customers on this site and this building represents a commitment to the downtown area," Olson said.

Reporter Michael Moore can be reached at 523-5252 or by e-mail at mmoore@missoulian.com.