Page 36 - Green Builder Sept-Oct 2020 Issue

DOE Annual Building Science Roundup A BETTER WAY

GARAGE

BEDROOM/
OFFICE

KITCHEN

DINING
LIVING ROOM

MASTER BATH
BEDROOM

Advanced glazing. Triple-pane sliding-glass doors and Weather warrior. Zero Net Now’s
windows allow ample natural light into the home while
GREENHILL CONTRACTING project in Newburgh, New York,
minimizing heat transfer. CREDIT: COURTESY OF ZERO NET NOW
Newburgh Custom, ƒ„ˆŽ resists hurricanes, earthquakes,
wildfires, tornados, blizzards,
mold and bugs—thanks to its
“The design and construction utilizes To allow for an abundance of natural all-foam construction.
highly durable, moisture-tolerant materials light without sacrificing too much in CREDIT: COURTESY OF ZERO NET NOW
and best practices for water-management so thermal performance, the builder opted
the structures may serve as safe, comfortable for high-efficiency triple-pane windows.
homes for many generations to come,” says The windows are argon-’lled vinyl-framed
Zero Net Now founder Anthony Aebi. “These casement style windows with an insulation
reinforced concrete structures are designed value of U-„.ˆ” (R-‰.‰‰) and a solar heat
to survive severe winds (above ƒ„„ miles gain coe•cient (SHGC) of „.ƒ‘. Even the
per hour) and earthquake activity, creating a sliding doors are triple paned. They have
safe haven for the occupants. These building an insulation value of U-„.ƒ„ (R-‰) and an
materials and strategies also create a pest- SHGC of „.ƒ”.
proof environment.”
Aebi constructs a sealed, unvented attic WHERE’S THE AIR?
that is insulated on the underside of the The home is so airtight that a blower door
foam serves as a vapor barrier and under- roof deck with two types of spray foam. He test of whole-house air leakage showed the
slab insulation. sprays ˆ„.‰ inches (R-‹Œ) of open-cell spray home had leakage of only „.ˆ” air changes
The ICF blocks are sealed at the seams foam, followed by ƒ.‰ inches (R-ˆŽ) of closed- per hour at ‰„ Pascals pressure dišerence
to provide a continuous air barrier. They cell foam insulation which completely (ACH ‰„). That level of airtightness (which
also serve as the drainage plane on the covers the open-cell spray foam, providing is typical of Aebi’s homes) is far below the
exterior side of the walls, so no house wrap a total attic insulation value of R-Œ‰. The ‘ ACH ‰„ required by the ƒ„ˆ‰ IECC and
is needed. To protect the framing where closed-cell spray foam also serves as a Class even well below the „.Œ„ ACH ‰„ required
windows or doors will be installed, an II vapor retarder. The insulated attic serves in the Passive House Institute U.S. standard.
elastomeric waterproofing compound is as a conditioned space for the ducted mini- To provide fresh air for the home, an
applied with a caulk gun and putty knife split HVAC system. Above the roof deck, a energy recovery ventilator (ERV) runs
to provide a seamless, jointless flashing self-adhered bitumen membrane is installed œž⁄¡ at low speed to exhaust air from the
layer around the openings. Vinyl siding is at the roof edges and valleys and the roof bathrooms, kitchen, laundry and attic. The
used for the exterior cladding. Below-grade is covered with enhanced-performance ERV is equipped with CO sensors that will
ƒ
portions of the ICF walls are protected with shingles that have a ˆ‘„ mph wind speed trigger higher levels of ventilation when CO ƒ
cementitious boards. rating and a lifetime warranty. levels exceed ˆ,„„„ ppm. The main controller

34 GREEN BUILDER September/October 2020 www.greenbuildermedia.com

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