Austin's Block 21 ranked one of world's most eco-friendly buildings

"I wish I could tell you there was nothing to it, but that would be a lie," he stated.

The 37-story building located in the 2nd Street District is the first and largest mixed-use building of its kind to achieve LEED certification. In addition, the ACL studio is one of two music venues in the nation to meet these standards due to features like LED stage lighting that dramatically curbs energy use.

Block 21 also includes shops, restaurants, a spa and entertainment venues.

Armstrong said he wanted to dispel the myth that it is more expensive to "build green."

"Is a Cadillac more expensive than a Chevy?" he asked."Of course it is, but it is a better product. It performs better and is therefore more valuable."

Armstrong said every project the developer works on will be part of the green initiative.

"We think green properties add to our bottom line," he stated.

Mayor Lee Leffingwell, who awarded the AE ranking, said the design saves money in the long run through reduced utility costs.

"We're very proud," Leffingwell said. "The City of Austin believes in this, and we will try to incorporate green standards in everything we do."

According to Stratus' case study on Block 21, the design includes water and energy efficiency features and used recyclable, regionally-sourced construction materials.

Specifically, Block 21 has high-performance plumbing fixtures and dual-flush, low-flow toilets that result in annual water savings of 2.4 million gallons. High performance lighting, glazing and insulation was also used to conserve energy.

Additionally, the project diverted more than 75 percent of construction debris from landfills for recycling and reuse.

Rick Fedrizzi, president, CEO and Founding Chair of the U.S. Green Building Council, said the city has done so much positive work.

"And I can promise you [that] it doesn't stop at the border of Austin," Fedrizzi said. "This is what goes out and is talked about around the United States and the world."