The anthem from “Rocky III” blared through a church one recent Friday morning.

Congregants, wearing caps and flannels and tagged with tattoos, bounced in their sneakers in preparation for the day’s sermon.

Instead of Methodists filling the sanctuary of the 1839 house of worship, the visitors are youths with trouble in their not-too-distant past. “I was locked up for a while and that was my community,” said Jesse Battista, 20, of Lowell, addressing the morning gathering called Fresh Inspirations at the United Teen Equality Center.

Now in its 13th year, the nonprofit that gives gang-afflicted, crime-ridden, and disenfranchised Lowell 16- to 24-year-olds a second chance finally has a space befitting its mission. Using the latest in green technology, the once nomadic drop-in center has turned a crumbling church into an icon of sustainability and secured its future.

“We are not just building a green building and leaving it at that. It’s a model for high-performance energy efficiency,” said Gregg Croteau, UTEC’s executive director, on a recent tour of its sleek new atrium awash in natural light.

UTEC’s $8.5 million green urban youth center officially opens this month. With funding from the city of Lowell, federal stimulus aid, and several well-known charitable foundations and individuals, the repurposed space is “a harbinger of things to come,” said Susan Kaplan, director of marketing for the Massachusetts Department of Energy Resources.

The state agency allocated $1.9 million from the American Recovery and Reinvestment Act to help UTEC retrofit the church into a sprawling space for teens to dance, learn algebra, debate politics, and become environmentally aware.

The building’s highlights — such as soy insulation, a passive cooling system, and electric car-charging stations — mean the teen center is “becoming sophisticated,” said Phil Hall, an administrator at the Theodore Edson Parker Foundation, which gave UTEC a $300,000 grant for the project. “UTEC really is that model of urban youth programming. It stands out as a model of excellence.”

What was once a packed chapel is now a performance and conference space for dance jams and movies, and big enough to host a Ted Talk. On top of the church is a network of solar panels, which will cut energy bills considerably.

Perhaps the most visible change is the cafe, which will open next year to the public. In an angular space furnished with repurposed wood from the church’s original floor, the youth-run restaurant will serve farm-to-table meals and homemade bread from UTEC’s Fresh Roots culinary arts program.

To add clout to its efforts, UTEC has applied for LEED (which stands for Leadership in Environmental and Energy Design) platinum certification from the US Green Building Council. If approved, the center will be the oldest building in the country with that distinction. In this business of confidence-building, such accolades make a difference.

“The environment dictates the behavior of our young people,” said Croteau, adding that UTEC members had a green building on their wish-list from day one. “Young people have always been in the lead. They create movement.”

And lately, there’s been major movement at 34 Hurd St.

Thanks to an 8,000-square-foot addition, UTEC will double enrollment in its alternative high school/job training programs while reducing energy consumption by 68 percent. But, akin to Rocky’s rise to the top, this is a story about the will to survive.

In a city with 25 active gangs, according to the Lowell Police Department, UTEC has had a constant demand for its services.

The organizations started out as a group of reformed gang members roaming the city’s most violent neighborhoods to keep the peace.

But street workers soon realized they could not break through without “a safe haven, a neutral zone,” said Croteau.

Bouncing around church halls and vacant rooms above storefronts since 1999, the nonprofit purchased the church in 2006. Dingy with pigeon dung, a leaky roof, and cracked windows, the building was so outmoded, it cost the parish $5,000 a month to heat the space with an old boiler, said Croteau. UTEC moved in the following year and began raising funds to improve the historic structure with efficient and green updates.