"Globally today we're focused on three areas: inner cities, proper downtowns and emerging neighborhoods. We think people are comfortable in live/work/play environments."

And its not just the majors that are of interest to Thor, Sitt adds. "The safety and revitalization that's taken place in New York is happening in the rest of America and the live/work/play dynamic is filtering to other cities."

At the same time, he continues, "Companies like Amazon, Facebook and other new entrepreneurial businesses like to have employees in affordable communities. So we've expanded our horizons into those cities as well as areas beyond traditional real estate interests. Like here in New York, that's Brooklyn, Queens and the Bronx; in Chicago it might be the West Loop, and I can go on. That's what's driving Thor to become bullish on 18-to-22 hour cities and not just 24-hour cities."

Despite what had been conventional wisdom, Sitt doesn't foresee a reduction in the need for commercial space. "Everyone said technology would reduce the need for real estate in the office sector—because storing information digitally would eliminate on-site storage needs—and retail because of online shopping."

Yet, he noted, "In Seattle, office rents are doubling and tripling because the need is growing faster than supply and, in the case of retail, today's hottest sector—is our tenant today. The best example of that is the Samsung Building, at 837 Washington St.."

Still, on the retail front, as well as on a general industry issue, Sitt sounded some cautionary notes.

Earlier this month, Bulgari set a new retail rent record of over $5,000 per square foot —and possibly as much as $5500 per square foot after free rent and other considerations—bringing its annual rent in a new lease at 730 Fifth Ave. to more than $16 million.

"Seeing such high real estate values makes us nervous so we're careful," Sitt warned. "Another thing we're worried about is interest rates. They will go up, and when that happens, the fact that you could go away with something on a property a year or more ago doesn't mean that you still will."

But the worrying has helped Thor, and Sitt, achieve industry longevity, he said. "Only the paranoid survive."