The emptying out of downtown Buffalo’s tallest building should not be looked at as a threat, but a chance to reposition the 40-year-old tower and take advantage of the rampant redevelopment around it, the head of an outside panel of real estate experts said Monday, after arriving in town to review future options for One HSBC Center.

Citing the massive economic investment happening in the city now, Charles A. Long said the timing presents the tower’s New York City-based ownership group with an opportunity to capitalize on the activity.

“This is a 40-year-old building. It would need to have attention paid to it, in terms of updating it and making it modern, in any case,” said Long, a developer from Oakland, Calif., who is chairing the panel from the Urban Land Institute.

“And so the circumstances that the owners of this building face could be looked at not as a disaster but as an opportunity. This is a great building in a great location, and it probably needs to have some reinvestment now anyway to respond to the modern marketplace and the demands that that marketplace creates.”

The mammoth building certainly faces challenges from its size and intimidating structure, as well as a large balloon mortgage, Long acknowledged. But it’s also adjacent to more than $500 million in development under way on various projects at Canalside, which is part of more than $1.5 billion in economic projects now under way in the city. It straddles Main Street, which the city is reconfiguring for revitalization. And it’s a subject of significant attention by city leadership, he noted.

“This is the heart of commerce in the region, downtown Buffalo, and it’s important that we really look at future uses of this building in a very strategic way,” said Buffalo Mayor Byron W. Brown. “This building is critical to the future of this community, to continuing the progress that we want to see in this community.”

Indeed, Long praised the “community leadership” in Buffalo, which he called a “prerequisite to something beneficial happening.” He cited the city’s emphasis on creating more residential space and “making the downtown more attractive for moving residents into downtown,” as well as the growth of the Buffalo Niagara Medical Campus and University at Buffalo’s decision to move its medical school downtown. “The $1.5 billion that the mayor mentioned is not by accident,” he said. “It’s the result of a community that has great community leadership.”

And that leadership, as well as concerted action not only by the building’s owners, but the community at large, is necessary for success, he said. “This is a problem that’s not going to be solved by Thursday,” Long said. “It’s a problem that’s going to require the community’s leadership to pick up the ideas and move ahead with an implementation program that’s responsive to the challenges that we face.”

The volunteer panel from ULI, an internationally renowned nonprofit land-use organization, was brought in with the help of a $10,000 grant from the city’s Buffalo Urban Development Corp. to help Seneca One Realty, owners of the tower, to find a new use for their 38-story building.

Constructed and opened in 1972, the 853,000-square-foot tower will go from 90 percent occupied to 95 percent vacant by year-end, after its two largest tenants – HSBC Bank USA and law firm Phillips Lytle LLP – leave in October and December, respectively. That means more than one-fifth of the downtown area’s 4 million square feet of Class A space could be added to the vacancy rolls all at once.

“We’re not sitting here feeling sorry for ourselves. We feel there’s a tremendous opportunity,” said Stephen Fitzmaurice, chief operating officer for Seneca One.

Among options under consideration would be a conversion into a mixed-use structure, equally divided between condominiums, office space and a “four- or five-star hotel,” Fitzmaurice said. The top floor would again be a restaurant or banquet center, as it was over 17 years ago, followed by an observation deck on the 37th floor.

Of course, officials would still have to assess if there’s enough demand for more hotel space, given the hotels already in operation downtown and pending plans for more as part of other projects. The same would be true for office space and condos.

The tower’s wraparound buildings at the base, occupied by the bank for 39 years, also pose the possibility of unusually large urban floorplates of as much as 52,000 square feet.

In the meantime, Fitzmaurice said, it’s premature to predict exactly what they will do, how much it might cost, or where the funds would come from, though the final tally could easily rival the original $93 million purchase price for the building in 2005.

On Monday, the six-member team of developers, architects and economic development experts from ULI – who started arriving late Sunday night – began a marathon three-day examination of the building’s prospects for redevelopment.

The process will involve tours of the building and the downtown area; a briefing book of more than 100 pages of written materials from Seneca One; interviews with over 40 local developers, bankers, government officials and other community leaders; and a late-night or even overnight session to hash out ideas and prepare a report.

It will culminate Thursday at 9 a.m. with recommendations to the public. “It just shows the depth and breadth of experience that the Urban Land Institute has in conducting and engaging in these kind of processes,” Brown said.

But Long cautioned not to think that’s the end. “Good ideas by themselves are useless. The difference between a good idea and a good idea that works is work,” he said. “Hopefully we leave with the community good ideas that they’re willing to spend their time and energy making work.”