Page 33 - Green Builder Sept-Oct 2020 Issue

DOE Annual Building Science Roundup A BETTER WAY

and wood-to-concrete seams were caulked. meets all of the requirements of the EPA
The below-grade walls of the basement Indoor airPLUS including the use of low and
were poured concrete that was protected no-VOC and formaldehyde-free products. KEY FEATURES
on the exterior by a spray-on crystalline While a beautiful home and low-energy bills
waterproofer, -inch rigid foam, and a plastic are the result, Mantell-Hecathorn’s attention WALLS: 2-by-6 24-inch on center advanced
drainage board. The interior walls of the to detail and focus on quality construction framing, R-38 total: 5/8-inch drywall. In cavity
basement level were framed -by- -inch are what they are most proud of. 2.5-inch closed-cell spray foam plus 3-inch loosefill
fiberglass. On exterior, coated OSB sheathing,
on-center stud walls, with inches of closed- “We focus on high performance, not 2-inch rigid foam, rainscreen under stucco or stone,
cell spray foam, giving the below-grade walls just energy efficiency and lower utility or 3/4-inch furring strips under siding.
a total insulation value of R- . costs, but also building durability, ROOF: Shed roof, 5⁄8-inch coated OSB sheathing,
The home achieved an air tightness of . something homeowners can pass down ice-and-water shield, metal roof.
air changes per hour at  Pascals. To provide to future generations,” says Hunter ATTIC: Cathedral ceilings: 3/4-inch tongue-and-
ventilation, a heat recovery ventilator was Mantell-Hecathorn. groove Douglas Fir, 5/8-inch drywall, 11- 7⁄8-inch
installed to bring in fresh air through a I-joists, R-19 batt, 7-inch closed cell spray foam.
MERV  €lter and to exhaust stale air. The IT’S ALL ABOUT TEAMWORK FOUNDATION: Insulated basement, R-23 total:
HRV was separately ducted to provide fresh The company lives up to its motto, “personal 55/8-inch drywall, 2-by-4 studs, 24-inch on
air to every room in the house and to exhaust attention to detail, one home at a time,” center; 3-inch closed-cell spray foam, 8-inch
air from several locations, including the limiting projects to two or three per year, poured concrete, water proofing, 2-inch rigid
kitchen and bathrooms, which have boost so that Hunter or Greg can personally be on foam, drainage board.
switches to more quickly remove steam. site daily to ensure that quality standards WINDOWS: Triple-pane, low-e2, aluminum clad
wood fixed frames, interior motorized blinds,
U=0.19, SHGC=0.50.
Open wide. Carefully placed windows and lights brighten
up the interior while also conserving energy.and lights AIR SEALING: 1.5 ACH 50.
brighten up the interior while also conserving energy. VENTILATION: HRV, continuous ventilation, boost
switches in bathroom, MERV 13 filters.
HVAC: Radiant floor heat from wallhung gas boiler,
96 percent AFUE; 22 SEER AC; passive solar.
HOT WATER: Wall-hung gas-fired boiler, 96 percent
AFUE, 80-gallon push button recirculation pump.
LIGHTING: 100 percent LED, integrated lighting
controls.
APPLIANCES: ENERGY STAR dishwasher, clothes
washer and refrigerator.
SOLAR: 7.2-kW PV system.
WATER CONSERVATION: WaterSense fixtures;
drought-resistant landscaping.
ENERGY MANAGEMENT SYSTEM: Smart
thermostats, lighting automation, PV tracking.
OTHER: Aging-in-place, all low-to-no-VOC and
formaldehyde-free products.

A † percent e‡cient wall-hung boiler are being met by the subcontractors and into €nding subcontractors willing to meet
provides domestic hot water to the home crews. Mantell-Hecathorn Builders employs their standards. Mantell-Hecathorn meets
and hydronic radiant ˆoor heating to all five full-time carpenters who receive with subs during budget formation and
three ˆoors. Passive solar gain adds to the training, construction documents and daily plan development, provides written scopes
space heating. Cooling is provided by a oversight. of work for each trade detailing construction
SEER heat pump. “We don’t experience much turnover methods and materials, requests the
Energy Star appliances, LED lighting, and in our employees, as we always have best crews, and meets regularly with the
low-ˆow EPA WaterSense-labeled €xtures interesting, challenging, and fun projects to principals and the onsite supervisors for each
add to energy and water savings. work on,” says Hunter Mantell-Hecathorn. subcontractor trade during construction.
A main-floor master bedroom and “They can feel pride in their work, and we “Quality construction is something we take
elevator are among the aging-in-place treat them as valued, respected members a lot of pride in, and our company is known
features designed into the home. The home of our company.” The company put ešort for that dedication,” he says.

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