This week I listened in as graduate students in Colorado State University Professor Brian Dunbar's Institute for the Built Environment class presented case studies on green homes. For its holistic approach and overall charm, Hacienda de Hunt in Taos, New Mexico, stood out as publish-worthy.
Student Elliot Dale lived for a month in the 2,200-square-foot home, built by John Hunt of Alternative Construction for about $110 a square foot, so he understands firsthand the benefits of super insulation, daylighting and attention to indoor air quality. The home’s passive heating system relies on 8-inch Trombe walls that store the sun’s heat and allow it to enter the interior space at night. The stucco-clad home is insulated with R-65 cellulose made from recycled newspaper in the roof, R-10 water-based rigid foam under the slab and R-40 18-inch pumice-crete in the walls, which expand to R-50 at the base and corners, where heat loss is greatest. “Super insulation is like putting a sweater on your house,” John Hunt explains.
The home’s roof slopes from north to south with extreme ventilation on both sides. Trusses in the roofing system allow for three times the required air flow, and all windows are operable. (We talked in class about how crazy it is that this basic—and simple—step to good indoor air quality is so often overlooked.) The home’s passive heating system eliminates the need for forced-air heating and cooling, which also cuts down on dirt and particulates. High windows also help reduce particulate infiltration, and low-VOC sealers, plasters and finishes contribute to the home’s clean air. Transom windows are used above all doors and interior rooms to maximize daylighting, and every room has two sources of natural light.
The home is carefully sited to take full advantage of the sun and prevailing winds. Trees and fencing block wind on the home’s west, east and north sides, leaving the south side open for passive solar exposure. The garage provides a wind break on north side, and rooms are configured so all occupied spaces are on the south side and storage buffers the colder north end.
In arid New Mexico, water conservation is crucial. Hacienda de Hunt’s roof catches rain water to irrigate cherry, apple, peach, apricot, pear and aspen trees planted around the house, and grey water is used to water mint and currants. (About 80 percent of the household water is reused.) John Hunt is reclaiming the native pasture land and has already saved the property’s junipers from a mistletoe invasion. Inside the house, John installed water-efficient showerheads, toilets and aerators and a hot-water recirculation system.
“This house is special to me since it was my first introduction to sustainable, energy efficient building,” Elliot told the class. “I knew many of the sustainable attributes of this house beforehand, but this case study project allowed me learn them all in a holistic way.”
I wish everyone could have such an opportunity.
The passive solar home is carefully sited to take advantage of the site's southern exposure and block winds. Photo by Elliot Dale
High windows and bottles embedded in the walls bring light into hallway spaces. Photo by Elliot Dale
Super insulation, operable windows and low-VOC finishes make for superior indoor air quality. Photo by Elliot Dale