Deltec Homes built this 1,759-square-foot custom home in Mills River, North Carolina, to the high performance criteria of the U.S. Department of Energy Zero Energy Ready Home (ZERH) program.

A 6.5-kW roof-mounted solar system helps the home achieve a Home Energy Rating System (HERS) score of 0, meaning the home produces as much energy as it uses over the course of the year.

The home is equipped with an ENERGY STAR refrigerator, dishwasher, water heater, clothes washer, clothes dryer, master bath exhaust fan, and ceiling fans. The clothes dryer is a condensing dryer.

Clerestory windows and LED lighting provide efficient lighting to the home.

WaterSense-labeled faucets reduce energy and water usage.

An inch of rigid XPS foam and draining house wrap surround the 2-by-6, 24-inch on-center stud walls, which are also stuffed with 5.5 inches of grade-I-installed unfaced fiberglass batt insulation.

Low-expanding foam around all window and door openings is one of many air-sealing details in the house. Also, thorough caulking of all top plates, bottom plates, wall panel joints, wall panel centers, and all electrical, plumbing, and HVAC penetrations; spray foam attic insulation; sill-seal gaskets under the sill plates; and gaskets between the plywood sheathing and the framing of each wall panel. These details helped the house achieve an airtightness of 1.44 air changes per hour at 50 Pascals.

The unvented attic is insulated on the underside of the roof decking with R-30 (8 inches) of open-cell spray foam. While most of the home has vaulted ceilings, a small area of attic over the hallway provides an insulated space for the ducted mini-split heat pump that conditions the bedrooms.

The 2-by-6 wall panels for the home were constructed in a factory where gaskets were installed on the outside face of the framing to provide an airtight seal with the plywood sheathing.

The wall panels were constructed in a factory where gaskets, plywood sheathing, exterior rigid XPS, windows, and insulated headers are installed. Draining house wrap, batt insulation, and fiber cement siding are installed at the site after the panels are assembled. The total dry-in time from delivery of the panels to assembly, roof truss and sheathing construction, house wrap, roof wrap, and door installation is just four days.