Rana Creek’s office is a breezy, light-filled wooden lodge tucked into the bucolic folds of Carmel Valley, with cows and horses for neighbors. It’s a low-profile headquarters for an increasingly high-profile design and build firm, which turns roofs and walls into green, breathing habitats.

Most of Rana’s environmental planning and nursery clients are in Monterey County, but up to 90 percent of its living architecture work is elsewhere, Executive Director Paul Kephart says. It’s that work – a penchant for covering walls and roofs with plants, recycling water and making developments hospitable to wildlife – that has earned the firm international renown.

Rana is especially well known for its “living roofs,’’ which offer economic as well as environmental payoffs by conserving energy, capturing and filtering stormwater runoff, muffling ambient noise and laying out a green carpet for native plants and animals.

The firm has helped design some of the world’s most famous living roofs – at the California Academy of Sciences in San Francisco’s Golden Gate Park, the Vancouver Convention Center, The Gap headquarters in San Bruno, and the Stanford Medical Center’s garage.

Current design projects include vegetated roofs and walls, bioswales, rain gardens, wastewater treatment systems and solar panels on an affordable housing complex in San Jose, a city hall building in South Los Angeles and an environmental justice center in S.F.’s Hunter’s Point.

Rana’s other projects, Kephart says, include the biggest living roof in North America, a 9-acre driving range capping an underground water treatment plant in New York City. Similar designs are in the works for S.F.’s Ortega Public Library, the Miami Science Museum, and Monterey Bay Shores, a proposed eco-resort on the coastline of Sand City.

Another design involves an engineered wetland inside a corporate building in Monterrey, Mexico. The DeAcero fence company building will include three living roofs, 30-foot indoor living walls, a landscaped central atrium, and a terraced indoor wetland garden that treats 100 percent of the building’s wastewater on site. The system, which recycles more than enough for all of the building’s non-potable water needs, is expected to save almost $40,000 in annual water fees and pay for itself within two years.

Despite its green deeds, the fact that Rana works for developers and agencies at times pits it against environmental groups. In spring 2007, Rana defended the use of Roundup herbicide on the Pacific Grove dunes, despite opposition from coast preservation group Surfrider. Yet Kephart says he’s generally against pesticides and skeptical of the war on invasive species.

Rana has also designed developments that some would prefer not to be there at all. The Monterey Bay Shores resort, sited on Sand City’s coastal dunes, may best illustrate the predictable pushback against sensitive developments, no matter how green: Monterey Coastkeeper and Sierra Club are among the groups critical of the project.

But Kephart is tired of what he calls the “totally boring” developer-conservationist divide. Growth happens, he says, but it should be done in a way that conserves water and energy while providing habitat integrated with the built environment.

“We’re pulling the wings of a butterfly apart,’’ he says. “We don’t have to do that.

“That’s what’s exciting about our new green movement: It provides us with a promise and a hope. We feel good when we can say we’re restoring butterfly habitat, but when we provide the economic impetus so that these things pay for themselves, that’s when we win.”