Page 22 - Green Builder Magazine Sept-Oct 2021

Key Features

AIR SEALING: 1.37 ACH 50; foam gasket and caulk
at sill plates; open-cell spray foam in rim joists.

APPLIANCES: ENERGY STAR dishwashers,
clothes washer, clothes dryer and refrigerator.

ATTIC: Vented attic: 14-inch R-49 blown-in
cellulose; 14-inch R-50 open-cell spray foam in
attic floor above garage and porch.

ENERGY MANAGEMENT SYSTEM: Smart
climate controls; smart thermostat; solar tracking.

FOUNDATION: Unvented crawlspace; CMU walls
insulated on interior with R-11 Batt; 8-mil vapor
barrier over dirt floor; R-19 open-cell spray foam
in rim joists.

HOT WATER: Energy Star-certified, 50-gallon,
heat pump water heater; UEF 3.42, button-
operated recirculating pump.

HVAC: Central heat pump, 10 HSPF, 19.8 SEER;
rigid metal ducts.

LIGHTING: 100 percent LED; smart house
system controls; daylighting. then filling the wall cavities with fiberglass design incorporates some special fea-
batts—in this case, R-19 batts that are tures. The truss design is strengthened
ROOF: Gable truss roof: R-49 insulation, plywood compressed to R-16. from 10 pounds to 15 pounds per square
sheathing, fire and ice underlayment, ridge vent, The exterior sheathing is an oriented foot to accommodate solar panels.
architectural shingles; 14-inch raised heel trusses; strand board (OSB) product that has R-3.5 The trusses incorporate a 14-inch
8⁄12 pitch (optimal) for solar panels. of rigid foam adhered to the interior side raised heel to prevent cellulose from being
and a plastic coating on the exterior side compressed at the eaves. The floor joists
SOLAR: 5.94 kW; 18 rooftop panels, central inverter. that, when the seams are taped, serves as a are insulated with 14 inches of open-cell
weather-resistant barrier and air barrier. spray foam anywhere rooms are located
VENTILATION: ERV; MERV 8 or 13 filter supplies The rim joists are also sealed and insu- above unconditioned space, such as with
air to return of central heat pump, pulling from lated with 5.5 inches of open-cell spray the garage or porches. The roof itself is
two house locations. foam. Durable fiber-cement siding cov- sheathed with plywood, ice and water
ers the walls. The sill plate is sealed to the shield, and 30-year architectural shingles.
WALLS: 2-by-6, 24-inches on center, R-23 total: foundation wall with a sill-sealing foam Ridge and soffit vents provide ventilation
wall cavity flash and batt 1-inch open-cell spray gasket and expansive caulk. to the attic.
foam plus R-19 fiberglass batt or spray-in cellulose; The sealed and conditioned crawlspace Vinyl-framed, single-hung ENERGY
R-3.5 coated OSB exterior sheathing; fiber cement is insulated along the interior walls with STAR-rated windows have low-emissiv-
siding; open-cell spray foam in rim joists. Designed R-11 fiberglass batts that are wrapped in ity coatings and an argon fill to slow heat
with 3D Building Information Modeling (BIM). a vapor barrier and draped over the con- transfer. They have been tested for air
crete block walls so they can be lifted for tightness by the manufacturer at Healthy
WATER CONSERVATION: EPA WaterSense termite inspection. An 8-mil polyethyl- Communities. The double-pane windows
fixtures; drought-resistant landscaping. ene vapor barrier covers the crawlspace provide an insulation U-Factor of 0.28 and
floor. a solar heat gain coefficient of 0.22.
WINDOWS: Double-pane, argon-filled, low-e, The 8/12 pitch of the roof is an opti- The heat pump has a heating season
vinyl single-hung frames, U=0.28, SHGC=0.22. mum angle for solar production and yields performance factor (HSPF) of 10 and
enough space to set two rows of vertically a cooling efficiency of 19.8 SEER. The COURTESY OF HEALTHY COMMUNITIES
OTHER: EV charging station, low-VOC paints; UL mounted solar panels on the south side. central heating system incorporates an
GREENGUARD and Green Label Plus flooring; natural The roof trusses are 24 inches on center optional air cleaning technology that can
stone building material in bathrooms and entry. to align with the wall studs, and the truss remove up to 99.98 percent of airborne

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