Austin, Texas—with its "Keep Austin Weird" motto emblazoned on locals' t-shirts and bumper stickers—is ground zero for a green-building revolution, due in no small part to nearby University of Texas, hipster culture, and a booming technology startup scene. The self-proclaimed "live music capitol of the world" will also be the second U.S. city to get Google Fiber, an Internet-cable plan that Google promises to be 100 times faster than today's standard broadband.

The culturally liberal enclave in a vast red state might not be the first city that comes to mind when you imagine the future of Christianity. But when you're trying to figure out what God is up to, "weird" is a good place to look. And maybe the weirdest thing about Austin is not the Google Fiber streaming in its front door, but rather the treehouse in its backyard.

Just off of U.S. highway 290 in South Austin sits TreeHouse, a home improvement supply store for "smart building and better living," specializing in environmentally conscious installations that save energy.

Since opening in 2011 and seeing $3 million in sales so far, TreeHouse is one indicator that providing homeowners with more energy-efficient and sustainable products may be a business model as economical as it is ecological.

And biblical.

TreeHouse began in 2007 in Frisco, Colorado, as Evan Loomis and Jason Ballard, two of the original five co-founders of TreeHouse, found themselves sitting in a micro-brewery instead of skiing, hatching a plan to create the Whole Foods of Home Depot.

Loomis and Ballard had been looking for something like TreeHouse ever since their days at Texas A&M University, when they became close friends in the Aggie's Men's Club, sort of a purpose-driven frat house.

"Some of us are doctors, some have gone on to formal ministry, but we all shared this conviction that we didn't want to waste our life," says Ballard.

After graduation, Ballard took his biology degree and worked in sustainable buildings, while Loomis took his finance degree to Wall Street. But in Colorado, they stumbled upon an idea that married their experience and passions to a great need.

Ballard believes the way Americans currently build and maintain their homes uses too many natural resources and is detrimental to our health. Loomis was simply jazzed about the numbers.

"From a business standpoint, it was an incredible idea," said Loomis. "Apparel had Patagonia. Grocery had Whole Foods. But home improvement was pretty bland. No one was doing anything meaningful for health and sustainability."

The foundation of the TreeHouse business model is extending "Common Grace for Common Good." Ballard, an Anglican (Loomis calls himself "Anglican friendly"), is confronted by the obligation expressed throughout the Anglican liturgy to reach out to the surrounding community.

"If you are praying out the liturgy, the idea of the common good is always there. It haunts you," he says.

Planting Deep Roots

If the TreeHouse mission statement, the "Roots" document, reads a bit like a manifesto, that's because it functions as one. Each of the document's tenets was prayerfully developed to reflect a core element of the gospel, and then is ordered by importance.

The first tenet, People Matter, is a message at the heart of the biblical narrative. Next, that care must radiate to communities and, after that, nature. Only with these three in place can TreeHouse hope to accomplish the fourth element: a commitment to deliver products and services that are truly excellent, that do not harm in the process of helping.

Finally, Dreams Matter. "It comes at the end for a reason," said Ballard. Dreams, of all the pieces of the Roots document, points to living in the hope of the return of Christ.

Loomis and Ballard recite a little axiom to remember their mission. It's a simple string of verbs that sounds like a conjugation exercise: was, is, ought-to-be, and will-be, a way of rehearsing the biblical narrative.

Living out that storyline is what for Ballard and Loomis makes TreeHouse deeply Christian. "If the Resurrection is true, it should influence how we live and behave toward everything," says Ballard.

Loomis and Ballard compare their approach to faith-informed business with other approaches by alluding to C. S. Lewis and J. R. R. Tolkien: Both authors approached their work with deep Christian motives, but Lewis crafted an explicitly Christian allegory in the Chronicles of Narnia, whereas Tolkien wrote the Lord of the Rings as a non-allegorical work yet one still pervaded by Christlike characters and themes.

Loomis and Ballard have even adopted a Tolkein-esque nickname for one of their mentors, Steven Garber, founder of the Washington Institute for Faith, Vocation & Culture. "If you want to engage the arts of culture or anything, he's your Gandalf."

Garber has consulted with Fortune 500 companies, but says the principles of biblical stewardship and sustainability apply just at well to anyone opening a hamburger joint. In fact, the former chairman of the Washington Institute, Hans Hess, did just that with Elevation Burger in 2005.

"Hans is making eschatological hamburgers," says Garber. Everything from the way the cattle are raised to the quality of the ingredients to the way Hess treats his staff points to the way life under Christ's reign ought to be. Garber likewise challenged TreeHouse to do business in light of redemption.

"What does it mean to build with materials that don't cost us things?" said Garber. "Maximizing profit is not sustainable; you have to be concerned about profits and people and the planet at the same time." For Garber, this is what it means to reflect the gospel in a way that points to Christ. "Evan and Jason aren't trying to get someone to sign the Nicene Creed in order to buy lumber," says Garber.

Answering these questions has had an undeniable, and sometimes dramatic, effect on TreeHouse patrons. One patron recently entered TreeHouse wearing a disposable face mask. After a timid few minutes, she slowly took the mask off and immediately asked to speak to the owners.

"I want to thank you because I can breathe in here." The patron was unable to shop in most stores because of her extremely high chemical sensitivity. The absence of those toxins is precisely what made TreeHouse a haven for her.

Clear Air for the Common Good

But the absence of toxins is like the absence of sickness: You hardly think about them until they interfere with your life. Ballard's wife was diagnosed with cancer in February 2012. A year later, his daughter had a series of unexplainable epileptic seizures. While the cause of such ailments is so often a mystery, Ballard can't help wondering if the toxins in building materials play some destructive role.

At the least, Ballard and other environmental experts know that buildings use more energy than any other single element in human society (including the often-maligned SUVs and nuclear power plants). According to the U.S. Green Building Council, buildings account for an astonishing proportion of CO2 emissions, nearly 40 percent, as well as 72 percent of all electricity consumption. According to the U.S. Energy Information Agency, buildings—residential and commercial—accounted for more than 30 percent of all energy consumption last year.

That means that when it comes to strategizing for how to steward resources, buildings jump to the top of the list. Austin happens to be a particularly great place to strategize. And TreeHouse's leaders were recently asked to help dream of a more sustainable future.

The University of Texas in Austin recently approached TreeHouse for help with a publicly funded research project called the Pecan Street Project. A partnership between the City of Austin, Austin Energy (the municipality's provider), the University of Texas, the Austin Technology Incubator, the Greater Austin Chamber of Commerce and Environmental Defense Fund, Pecan Street is an ongoing effort to establish a sustainable energy grid in a South Austin community.

Pecan Street invited TreeHouse to help study participants change their energy consumption habits. To do that, Ballard went to the homes of people that he would never have had the opportunity to meet otherwise. On one consultation, Ballard talked over coffee about sustainable energy, then life, and then his wife's cancer. All of a sudden, a publicly funded study offered the chance to relationally advance the common good. "I don't think people have that experience at Lowe's," said Ballard.

And if Austin is a prime location for TreeHouse, Loomis and Ballard couldn't have picked a much better time, either. Austin happens to be the fastest-growing city of more than 1 million people in the United States. The director of Austin Energy, the largest public energy supplier, has approached TreeHouse to host a radio show about how homeowners can save money using fewer resources. Austin's economic interest in ecology is understandable: With a population boom, the region will inevitably look for more power, possibly building nuclear power plants that cost billions of dollars and add sizable tax burdens to citizens. But if existing Austinites learn to conserve, those costs can be delayed.

Cost avoidance is a great benefit to cities. But Ballard thinks first about sickness avoidance. "I can't prove that toxins caused my wife's cancer, or that pollutants caused my daughter's epilepsy. But I know that some peoples' [sicknesses] are. If there's one less father who has to watch his daughter have seizures . . ." Ballard doesn't finish, leaving the expected phrase it will all be worth it unspoken. Maybe the phrase sounds trite compared to what he is trying to do with TreeHouse. Or maybe he just refuses to label TreeHouse as heroic when he's only trying to obey Christ.

"He'll never be able to thank me," he says instead.

But that is the nature of Common Grace for Common Good: Things are better, sometimes without us even knowing it.

Bret Mavrich is a technology journalist based in Kansis City. He blogs at BretMavrich.com.