You’ll always find Boulder on a Best-City-for list. Most recently, it was named #1 Top College Town (by Livability) and America’s Best Town for Startups (Bloomberg Businessweek). That’s reason enough for people to flock to the “People’s Republic of Boulder.” A local legend may explain why they stay.

“There is a myth that when the Arapahoe Indians were driven from the Boulder Valley by white settlers, Chief Niwot put a curse on the valley that would not allow anyone who comes here to leave, ultimately leading to the destruction of the beauty that surrounds this place,” reports E.J. Meade, design principal with Arch11, who visited Boulder after college and never left.

Local officials have created many policies to that end—and to varying effect. A rural buffer rings the city, and the entitlement process is described diplomatically as demanding. There is a 35-foot height limit throughout the bulk of the city. This is “detrimental to density, and density is by nature sustainable—it makes mass transit work, it makes neighborhood nodes work, it makes society work,” says Christopher Herr, AIA, a principal with local firm Studio H:T. “So Boulder faces a conundrum of regulations that are in opposition to a perceived identity.”

Adaptive reuse and urban infill in the downtown area are the main opportunities for development. The Onyx, designed by local firm Harvey M. Hine Architecture+Interiors (HMH), is a three-story, 25,000-square-foot mixed-use building featuring six residential lofts over street-level commercial space. Sited on the zero-setback 15th Street, it received the 2009 AIA Colorado North Chapter Merit Award for Interiors. Two other downtown projects are in the offing.

While private development slowed during the recession, state and local government projects continued. The city’s new Boulder County Regional Fire Training Center features a sloped roof and protective metal skin to block direct sun and harsh winds (the wind load is up to 140 mph in some parts of town). The LEED Gold–certified building earned the 2011 AIA Western Mountain Region Merit Award, 2010 AIA Colorado Citation Award, and 2010 AIA Denver Merit and People’s Choice awards.

The University of Colorado’s Jennie Smoly Caruthers Biotechnology Building is a 336,850-square-foot magnet for the institution’s biotechnology, biochemistry, and chemical engineering programs—and a catalyst for the bioscience sector, which employs more than 36,000 workers and generates more than $400 million in state taxes.

Where will Boulder be in 10 years? Harvey Hine, AIA, HMH’s founding partner, expects it won’t look “a whole lot different than it looks now. Most of the design work will be in renovation and not new construction. Some old shopping centers will be redeveloped, hopefully into mixed-use.” His partner, Cherie Goff, AIA, is hoping for more density and infill. “I think these are the only long-term ways to address growth without sprawl.”