Page 29 - Green Builder Magazine Sept-Oct 2021

DOE Annual Building Science Roundup
SILVER LININGS
Critical Mass

R-29 SIP walls, supported by ultra-efficient
HVAC and a heat recovery ventilator, mitigate
temperature swings in this exceptional home.

ETTING USED TO not fiddling insulation, the home is better than net zero. program in Seattle and Bellingham,
with the heating system was the Builder Ted Clifton, Jr., likes to call Washington, since 2004.
Gonly difficulty for the homeown- the building “energy positive,” produc-
ers of a new U.S. Department of Energy ing enough power to run the home and CARBON NEUTRAL GOALS
(DOE) certified Zero Energy Ready Home an electric car or two. The home’s Home TC Legend nearly always starts with a
(ZERH) built by TC Legend Homes in Energy Rating System (HERS) score super-insulated structural insulated
Everson, Washington. reflects this; a HERS score of 0 or lower panel (SIP) wall and roof over an insu-
“We were used to a forced air furnace would equal a net zero energy home. The lated concrete form (ICF) foundation.
with a nighttime setback temperature sev- TC Legend home achieves a -19 when The 2020 award-winning home is a
eral degrees lower than the daytime tem- the 12.4-kilowatt (kW) solar system is two-story, 2,538-square-foot home
perature,” says the homeowner. “But in a included. Even without the photovoltaic constructed on a slab-on-grade founda-
high-mass, super-insulated home, that sim- (PV) system, the home would score a tion with 5.25-inch ICF stem walls that
ply isn’t necessary. Even in cold weather, HERS 33, well below the HERS 80 to 90 provide an insulating R-24.3 perimeter
it would take several days with no heat to of typical new homes. around the structure.
cause a significant temperature drop. We The exceptional performance won TC The walls are constructed of 6.5-inch
don’t have to touch the thermostat.” Legend a Grand Award in the Custom for R-29 SIPs consisting of two layers of ori-
So, instead of experiencing daily tem- Buyer category of DOE’s 2020 Housing ented strand board (OSB) sandwiching
perature fluctuations of 64 to 72 degrees Innovation Awards (HIAs). This is TC a graphite-enhanced expanded polysty-
Fahrenheit, the homeowners are enjoy- Legend’s sixth DOE HIA winner and the rene core. TC Legend’s in-house crew
ing a constant temperature of 68 degrees. third Grand Award for the custom builder, can assemble the walls and roof in three
And thanks to exceptional air sealing and who has certified 27 homes through the days, because the panels come to the site

Average Monthly Energy Bill
$0 Climate IECC,4C, marine

Calculated
Dry (B) Moist (A)
Marine (C)
7
6
Annual Savings 4 6
$2,450 5 5

Calculated versus typical new homes 4

3
2 3
2 2
Saved in the first 30 Years
$103,200 1

Includes fuel escalation rates,
2019 EIA Energy Outlook

www.greenbuildermedia.com September/October 2021 GREEN BUILDER 27