Page 19 - CodeWatcher Spring 2017 Issue

A CONTRACTING is no stranger tion requirements of the EPA’s

BY CATI O’KEEFE NTHONY AEBI OF GREENHILL as well as the hot water distribu-

to awards for staying ahead (way
WaterSense program and the
ahead) of the pack. A winner of
insulation requirements of the
2012 IECC.
both the 2015 and 2016 Cross
Border Challenges, he won again
This house generates enough
in this year’s challenge for a
3,912-square-foot custom home,
to enable the homeowners
to charge a vehicle and still “When I first
Jewels Court, which boasts a -11
achieve zero energy, Aebi points
HERS score (with PV). What’s more, while he won “Lowest energy with its minus 11 score started building
HERS score American Custom Builder,” all his houses are out. “We achieved this with
built to exacting performance standards. things like a tight envelope and homes like this, I
“It’s how I build all my homes,” the Esopus, N.Y-based high-performing windows.” (See stuck my neck out
builder says. “It’s been my strategy since I built my first net “High-Performance Details,”
zero energy building in 2007.” page 18.) to show people
Greenhill produces homes that consistently net mid-20s what was possible;
HERS scores, dropping to 8-10 when PV is added. Structure Matters
Jewels Court is a DOE Zero Energy Ready home, which The shell of this home is con- they had to see it,
means it meets the requirements of Energy Star Certified structed of insulated concrete so I built spec
Homes Version 3.0 and the EPA’s Indoor airPLUS program, forms (ICFs), from the footing
to the roof line, which provides houses. This was
an R-22 insulation level. “If you 2007, and the
Greenhill Contracting built this are building like the ‘second lit-
3,912-square-foot house in Gardiner, tle pig,’ you can already see the public had no
N.Y. to the high-performance criteria problem with wood,” Aebi notes, concept of what
of the DOE Zero Energy Ready Home
program. The builder didn’t stop referring to The Three Little Pigs zero-energy meant
there: by adding 13.4-kW solar fable: “You need to think about
electric system, the home earned a resiliency. You need to survive with the massive
-11 HERS score and enables the tornadoes, hurricanes, and oth-
homeowners to live utility cost free. er disasters.” amount of
Outside, drought-tolerant turf and Aebi started the ICF walls greenwashing at
native plants eliminate the need for
landscape irrigation. below grade where they serve the time and the
as the foundation stem walls,
providing R-22 of slab-edge in- confusing
sulation for the basement floor definitions of Zero
slab. The slab was poured over
4.3 inches (R-27) of closed-cell back then.”
spray foam sprayed onto a gravel — Anthony Aebi,
base. The ICF blocks were sealed
at the seams to provide a contin- Greenhill Contracting
uous air barrier. They also serve as the drainage plane so
no house wrap was needed. An elastomeric waterproofing
compound was applied with a caulk gun and putty knife to
provide a seamless, jointless flashing layer around all of the
doors and windows.
Aebi constructed a sealed, unvented attic that is insulated
on the underside of the roof deck with two types of spray
foam: 11 inches of open-cell spray foam (R-4.45/in.) followed
by 2 inches of closed-cell spray foam insulation (R-7.4/in.) to
fill the roof rafter cavities and encase the rafters, providing
R-64 worth of insulation and creating a thermal break to
keep heat from transferring to the outside.
Above the roof deck, a self-adhered bitumen membrane
was installed at the roof edges, and valleys and the roof is
covered with enhanced-performance shingles that have a
130-mph wind-speed rating. High-performance triple-paned
windows complete the thermal envelope.

Spring 2017 / CodeWatcher 19