Anyone strolling past the new Portland, Maine, office of Richard Renner | Architects can see there's something going on here. The old commercial building wears a revamped, slightly abstract façade. Its new steel awnings sprout thick mops of greenery. A photovoltaic array stands watch on the roof. But there's even more here than meets the eye. By combining his firm's headquarters with his own home in an existing urban building—and by rehabbing that building as greenly as he knows how—Richard Renner, AIA, LEED AP, is really putting his money where his mouth is.

Green design is Renner's specialty—he penned the first house in the Northeast to earn a LEED Platinum rating—and he views existing buildings as an essential weapon in the battle to save the environment. “We're not going to build our way out of this problem,” he says. To bring this brick box up to standard, Renner spray foamed its walls and roof to R–34 and R–55, respectively; installed triple-glazed windows; and specified high-efficiency HVAC systems (including heat recovery ventilation) for both the office and the apartment. A green roof—480 square feet of low-maintenance sedum—reduces the summer heat load and rainwater runoff.

Renner's budget precluded seeking LEED certification for the office space—“It would have been at least $10 per square foot in soft costs to do it LEED NC,” he says—but it meets the same sustainability standards as the apartment, which earned a LEED Platinum rating. The living quarters, which Renner designed in collaboration with his wife, graphic designer Janet Friskey, employ abundant natural lighting, long sight lines, and a split-level plan to maximize the 1,400 square feet of living space. “It was a bit like doing a boat,” he says of the experience.

The building's envelope and systems perform as expected—first-year costs for heating, cooling, and domestic hot water totaled $423—but the environmental benefits of this rehab go further than that, Renner explains. The in-town location saves energy and carbon emissions, reuses both a building and an already disturbed site, and lends sustainability a little urban cachet. “It shows that you can have a very high level of environmental responsibility and not compromise the design,” he says.