The design for the Caterpillar House, sited on the softly rolling hills of the Santa Lucia Preserve, sought to accentuate a connection to the land. Having lived in a Cliff May home, the client came to the project with a love of modern ranch houses and looking for an environmentally-conscious response to a beautiful site. The Caterpillar House implements sustainable elements while exploring a contemporary version of the ranch ideals: massing that is low and horizontal, an open plan with a strong connection between indoor and outdoor spaces, and main living areas which center informally on the kitchen.Connecting literally and figuratively to the site, excavated earth was repurposed for the construction of the walls. These rammed earth walls gently curve in response to the site's contours and also act as a thermal mass, regulating temperatures from day to night. Capturing rainwater for irrigation, three tanks proudly sit close to the home - a clear sign of the available water resources for landscape. Large south-facing glass doors open the main living area to a large covered contemporary porch and to an outdoor patio with sunshades that expand and contract to allow for a flexible entertaining area that responds to the client's needs. The glazing, natural ventilation and operable shading also act as a passive heating and cooling system, cooling the house in the summer and warming the house in winter. Integrated photovoltaic panels enable the house to produce all of its energy requirements without compromising the graceful curve of the low roof against the hill.