At the end of 2000, Tryggvi Thorsteinsson and Erla Dögg Ingjaldsdóttir, Icelandic natives and partners in the Santa Monica–based design firm Minarc, bought what was essentially a teardown in the West Village neighborhood of Los Angeles. “We liked it for its simple lines and flat roof and thought we could do something with it,” Thorsteinsson says. But soon after the purchase, Ingjaldsdóttir’s first pregnancy and projects ranging from a Protestant church in South Central L.A. to a boutique hotel in Nigeria took precedence over the renovation. Five years and many spirited design discussions later, the new addition penetrates through the old frame, finally allowing the couple and their two children to call Minarc’s first environmentally conscious house home.

Where the structures merge, slots and gaps gracefully filter light announcing their separateness, as do contrasting materials: stucco for the original house and concrete panels by U.S. Architectural Products made of 30 percent recycled fibers for the new. “They were introduced as a faster way of building, intended to go underneath stucco,” says Thorsteinsson, whose interest in materials dates back to his years as assistant manager at Iceland’s largest hardware store, BYKO, in Kópavogur. “We come from a large country, relative to its small population, that doesn’t always think ‘green’ is so important,” he continues. “We believe being conscious about the environment, recycling, and using existing materials is vital. It doesn’t matter where you are in the world.”

In their all-in-one kitchen/living room-turned-playground, their daughter, four-year-old Carmen Inga, careens carefree around the oversized orange Corian kitchen island. The sides are clad in tough rubber recycled from tires, allowing her parents freedom from having to watch her every move. “I read rubber takes over 2,000 years to decompose. Perhaps it never really does, so we thought to reuse it and the kids would have a hard time wearing it out,” Ingjaldsdóttir explains of the material used more frequently in gyms and playgrounds.

During the renovation, the couple was not only committed to the reuse of materials but also rethinking the usefulness of materials, resulting in exceedingly simple organic solutions. All the walls, for example, are paint-free. “Why cover up the matte of the drywall? It’s white and the texture gives depth and richness. Let that be a part of the house, it’s beautiful,” says Thorsteinsson, indicating the exposed aluminum door jams. “We like to allow the materials to be what they are.”

Another significant aspect of the home’s earth-friendly approach is its ability to cool, and to a large extent heat, itself. During the five years before the renovation, the couple lived in the house and studied the movement of the sun and wind. When it came time to draw up plans, they oriented the new structure accordingly. “The sun rises behind the house and heats up the concrete mass during the morning, and [comes] through the front of the house in the afternoon; if need be the radiant energy warms up the house when temperatures drop in the evening,” says Thorsteinsson. Thanks to the thoughtful process, the couple was able to leave out the air-conditioning, and the house’s under-floor radiant heating system has turned out to be almost superfluous. Additionally, an enormous, pivoting front door ushers the Pacific Ocean breezes from the west inside, while a bank of sliding glass doors help keep the climate comfortable on the east side. On the second story, large openings—a sliding glass door in the master bedroom and sliding glass window in the office—dominate the front and back, recirculating fresh air, while narrow windows located at the south side minimize direct sunlight. “Even though we expanded the square footage of the house from 900 to 2,400 square feet, we have been able to cut our energy costs by two-thirds,” says Ingjaldsdóttir.