Page 19 - Green Builder March-April 2017 Issue

Wiseman and Evans took a 20-foot section of PVC to the site, so
they could test potential locations for visibility from below. They
learned that anything over 10 feet high was out of the question.
“Well,” said Evans, half joking, “we could bury it.” To their surprise,
the homeowners liked the idea. Wiseman began pulling together
images of old homesteads and potato barns that were half buried in
the ground, some with sod roofs.
Green roof. The final design, with its heavy roof form and low lines, pays
homage to those buildings. The home is nestled into the earth, which
Sod roof seeded shelters the structure from the strong winds and cold temperatures
with a mix of typical of the region.
native plants helps
the home blend THE SUN AND THE (ENERGY) STAR
into the landscape. The 3,611-square-foot home is spread along the east-west axis. Though
the home was oriented to maximize views of the Spanish Peaks, it
turned out to be advantageous to solar orientation as well.
Gallatin Gateway’s home is Energy Star certified and achieves a
HERS Index score of 48 without solar, thanks in part to an extremely
energy-efficient envelope. The shell is constructed of four main
components: buried concrete walls, exposed walls, green roof and
thermally decoupled flooring.
The buried walls consist of 8-inch concrete with 3.5 inches of rigid
insulation on the exterior (R-15), and a 2-by-4 furring wall filled in
with R-13 batts on the interior. The exposed walls are constructed
with 8-inch Structural Insulated Panels (SIPs) for an R-value of R-32.
The green roof consists of 4-inch Polyiso insulation (R-24) under the
membrane, combined with R-30 batts at the roof deck—a system
that eliminates unconditioned spaces in the attic. Gaco Western spray
foam is used to seal the truss heels and to glue the roof fiberglass
batts in place.
Constructive Solutions has been dedicated to Energy Star and HERS
for years, and the company owns blower door testing equipment.
“It’s standard for us to conduct two blower door tests,” says

PANTRY
GREAT
ROOM MASTER BATH
MUD MECHANICAL KITCHEN/DINING ROOM MASTER
ROOM BEDROOM
STORAGE

GUEST
LAUNDRY BEDROOM LIVING ROOM SCREENED-IN
PORCH
GUEST
BEDROOM
GARAGE

Main Level

March/April 2017 GREEN BUILDER 17

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