AUSTIN, Texas - What started as an experiment in sustainable construction 15 years ago is now known as the largest green community in Texas.

"Mueller is 100 percent a big experiment on many different fronts," said Greg Weaver of Catellus Development, the project's master developer.

The Mueller neighborhood in East Austin received the recognition as a nationally certified LEED Gold neighborhood from the U.S. Green Building Council. LEED stands for Leadership in Energy and Environmental Design and has three different levels: Silver, Gold and Platinum.

"Our goal is not toward efficiency," USGBC CEO Mahesh Ramanujan said. "Our goal is to actually go environmentally positive."

The USGBC certifies buildings that include renewable materials and are water and energy efficient. Ramanujan said projects like Mueller have helped move the construction industry forward, both locally and on a global scale.

"It's the place where they spend 90 percent of their time, so health matters," he said. "Importantly, it's an asset that needs to appreciate - not just by the pure market appreciation, but also with the things that they do with the building."

Mueller still has another five years of construction left. Weaver said it's designed to be a community for people from every socioeconomic background.

"The density here is one of the highest densities in the entire city next to downtown, and that was the push by the community here," which, he said, allows for a mix of incomes.

The LEED standards that are known worldwide, Ramanujan said, were born from Austin Energy's Green Building Program in 1991.

"That's a tribute to so many people that work so hard over so many years to make this a very livable community," Austin Energy's Debbie Kimberly said.

In addition to incentivizing efficient new construction, Kimberly said the utility aims to make aging homes and businesses more efficient.

"What can you do with existing buildings to look at bringing them up to a U.S. Green Building or an Austin Energy Green Building standard," she said.

Worldwide, there are more than 92,000 thousand certified green buildings providing more than 20 billion square-feet of inhabitable space.