Page 22 - Green Builder Sept-Oct 2019 Issue

High expectations. A host of energy efficiency features Annual Building Science Roundup 2020 A GRAND SYNERGY
ranging from solar panels to hygrothermic modeling help
make Thrive Home Builders ZEN 2.0 Collection net zero, with
Home Energy Rating System (HERS) ratings as low as 4.0.
COURTESY OF THRIVE HOME BUILDERS

home here has a calculated HERS score of 4). Even without the PV
The Zen system, the energy-efficient home would achieve a HERS score of 38.

DOUBLE-WALL DESIGN
Imperative The traditional farmhouse style of the home with its simple gable
roofs, front porches, and lap siding belies the sophisticated energy-
efficiency technology inside. Thrive used WUFI hygrothermic mod-
®
eling to come up with a wall design that would provide walls with
Thrive’s latest collection of net-zero a total insulation value of R-40 with low risk of moisture accumula-
tion. Thrive chose double-wall construction consisting of two 2-by-4,
homes takes building science and 24-inch on-center walls with staggered studs. The walls were spaced

planning to a new level. 2.5 inches apart to provide a 9.5-inch-deep wall cavity. After install-
ing half-inch OSB sheathing, crews sealed all seams with a sprayer-
BY GREEN BUILDER STAFF applied sealant and sprayed sealant along the top and bottom plates,
HE 41 HOMES THAT MAKE UP Thrive Home Builders’ before attaching drywall to form airtight gaskets. Then, the wall cavi-
ZEN 2.0 Collection at the redeveloped Stapleton Airport ties were filled with blown fiberglass. Textured house wrap provided
site in northeast Denver are all net-zero energy, thanks to a drainage plane behind the fiber cement and brick veneer siding.
the solar photovoltaic arrays on each home, and a host of The home’s vented attic was constructed with 14-inch raised heel
T energy efficiency and high performance home features. trusses to allow space for the full depth of insulation over the eaves.
Like every home Thrive builds, these homes were constructed to All of the top plates were air sealed with a sprayer-applied sealant
the criteria of the ZERH program. before installing the R-50 of blown fiberglass. The roof was pro-
Thrive has taken the extra step of installing a 7.93-kW solar PV tected with ice-and-water shield at all valleys and from the eaves up
system, as well as an energy storage system. All of the ZEN 2.0 24 inches past the wall line. The deck was covered with a synthetic
collection units come with enough solar panels to achieve a Home water-resistant underlayment and metal drip edge was installed
Energy Rating System (HERS) score of 15 or less (Thrive’s winning under the asphalt shingles.

20 GREEN BUILDER September/October 2019 www.greenbuildermedia.com

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