Years ago, everyone knew the office of the future: an open space, free-for-all. But that didn't pan out. Instead, the speakers at Bisnow's Denver Office of the Future event say flexibility is what tenants and their workers want—and they're getting it. (Predictions don't always come true: We often insisted the most famous Cyrus would always be Billy Ray.)

Though they represented rather different companies—an app-driven transit company and a multinational bank—Uber Technologies Denver GM Will McCollum (center) and Bank of America AVP Hampton Barclay agreed tenants are demanding an environment that promotes employee wellness and comfort. Open floor plates are important in many cases, since they promote the free flow of ideas, but workers also sometimes need more private workspaces, as well as flexible and technically sophisticated meeting spaces. Also snapped: Elsy Studios president Lynn Coit, who moderated.

Why is so much attention being paid to Millennials, since Baby Boomers and members of Gen Y are still very much in the workforce? One answer from the panel: Because they represent the future. Another: In certain industries, such as tech, they represent the best and brightest employees. Here's Industry & Stride partner Sean Campbell and Brookfield EVP Midwest & Mountain David Sternberg.

But more fundamentally, our speakers said, the goal is to create the best space for everyone—and everyone can appreciate natural light, fresh air and better amenities. Even office spaces that aren't particularly open are incorporating those features. Zeppelin Development partner Kyle Zeppelin and Transwestern managing SVP Lyla Gambow, who also moderated. Also speaking: John Madden co-CEO Blair Madden Bui.

For many companies, our speakers noted, open space is a good solution. The concept is filtering into the mainstream, and it's well understood that it promotes collaboration. It's also practically mainstream that buildings need to offer high-quality amenities. For example, buildings have long had fitness centers, but they used to be an afterthought in the basement. That's no longer acceptable for a property that's serious about creating a live/work/play environment.