The second architectural goal was to construct a building with a minimal energy footprint. The architects applied passive design principles to Casa Rosset, which is built into the side of a mountain, allowing the earth to naturally insulate the home. Natural light penetrates the home through the many glazed openings, while timber louvers shield the low-emission glazing from the harsh sun. The zero-energy home generates energy through geothermal, heat pumps, and solar power sources.