One of the biggest homebuilding attractions online recently has been a house that isn’t very big at all. Dubbed the Zero Energy Casita by its builder, Fort Worth, Texas-based Ferrier Custom Homes, this recently completed two-bedroom is only 1,051 sq. ft. and is designed to operate at net zero energy, or very near it.

Ferrier’s clients, in this case, use the house as a second home, and it does present as very much the cozy hideaway, with a rustic exterior and a lakefront view. But the design and material features of the house, from its siting and well-insulated shell to its use of reclaimed materials and renewable energy, give it considerable green cachet.

Don Ferrier, president of Ferrier Custom, favors the use of structural insulated panels for exterior walls and roofs on his projects, and this one was no exception. FischerSIPS, based in Louisville, Kentucky, produced the panels. The siding, however, departs from what’s typically found on a new house: the clients “wanted the house to look like it’s been there 150 years,” Ferrier says, so he used reclaimed siding for the skin and used salvaged flooring and 8×8 barn beams for interior finishes.

Low waste, high performance

Reuse and waste reduction actually were guiding concepts for most of the build: excess lumber and sheetrock were mulched on site for use in landscaping, and most of the plastics, metals, cardboard, and other jobs-site materials were recycled. The completed house includes rainwater catchment for irrigation, xeriscaping, Energy Star appliances, water-conserving fixtures, and low-VOC and formaldehyde-free finishes, adhesives, and countertop materials.

An air-source heat pump serves the house in the winter. To counter the Texas summer heat, the house is equipped with an air conditioner with a 16 SEER rating, and a high-efficiency particulate air filtration system. In addition to the SIP shell, a few other features help mitigate the energy draw of these appliances, especially during the summer: the siting of the house, which is shaded by a nearby oak tree and some 40-foot shrubs; a reflective, standing-seam steel roof with Galvalume coating; double-pane, gas-filled Weathershield windows with low-e coatings; and the renewable-energy system – a 45-foot Skystream wind turbine with a 3.7 kW capacity.

As noted in a recent Buildingonline.com post, the Casita scored a 30 on the Department of Energy’s E-Scale in preliminary tests. Not quite net-zero-energy performance, but still impressive. In an interview with Ecohome magazine, Ferrier noted that the house cost $312,000, excluding land. Since this is a showcase project, and Ferrier has committed to certifying every home it builds under LEED for Homes, the National Green Building Standard, Energy Star, the DOE’s Builders’ Challenge, and Green Built Texas standards, we’ll update this post when the ratings results are announced.