A five star-rated home in the Texas Hill Country, this Austin Energy Green Building proves that site-specific soft contemporary architecture and complete sustainable energy efficiency can be great go-togethers. The home was designed from the ground up by Donovan R. Davis to embrace the unique requirements of its owners regarding current and future livability and their passion for open and contemporary design and to deliver stunning panoramic views of the vineyard in the valley below. In addition to these specifications, the home delivered on the owners’ desire to achieve net-zero energy efficiency status while staying within a reasonable budget.
To reach such a lofty green goal, we collaborated with local net-zero energy builders early in the design process. Our unique design started with careful siting on the seven-and-a-half-acre site and continued with the integration of deep overhangs, copious day-lighting, an elevated stair tower with motorized windows for passive cooling, a ground-source geothermal HVAC system, a hybrid heat-pump hot water heater, banks of solar photovoltaic panels, and state-of-the art energy monitoring systems. The design also incorporated a sealed attic approach, spray foam insulation, and 100-percent rainwater harvesting for all water needs.
Literally beginning with a clean sheet of vellum, Davis sketched a beautiful exterior that pays homage to traditional Texas Hill Country design vernacular yet is at peace with its hilltop site, incorporating locally quarried limestone masonry, deep overhangs and porches, Galvalume® metal roofing, and varying widths of earth-toned HardiPlank® siding. Inside, Davis envisioned a straightforward yet open and airy floor plan, bringing to life the desire of the owners for a soft yet strictly contemporary design mantra while carefully segregating the public and private spaces. In keeping with healthful design practices, a detached garage and carport were connected to the house with a covered walkway in a zigzag configuration.
The end result is an everyday hillside retreat for its owners, with the added cost benefits of net-zero energy living. In addition to the Austin Energy Green Building (AEGB) five-star rating, the highest level of award available in the program, the home was also awarded a Home Energy Rating System (HERS) Index Score rating of Seven (7) (http://www.resnet.us/energy-rating) following an audit by an independent energy evaluation service. In actual practice, the all-electric home is performing very close to its near-net-zero energy design spec.