Page 53 - Green Builder Magazine March-April 2018 Issue

FROM THE
JUDGES
SCREEN
PORCH
“This simple,
MUD UTILITY
OFFICE ROOM
traditional PHIUS
BEDROOM MASTER design offers a
KITCHEN BEDROOM BEDROOM clear path to a
FIRST FLOOR LIVING ROOM SECOND FLOOR OFFICE solid, sustainable

home.”

was installed in the ceiling (R-90) and walls (R-60) to prevent loss of curve, which has everything to do with the fact that you measure
that temperature-treated air during transfer. Pedranti says they went things. That’s not the case with a typical, prescriptive code-built
way above Passive House minimums during installation. home,” says Pedranti, who has since taken on other Passive projects.
To stop heat loss through the concrete floor, Pedranti originally “With Passive, you build an energy model with a spreadsheet. It’s
planned to use a typical 12-inch layer of expanded polystyrene and very detailed; it’s down to three digits. Every bit of material, the
8 inches of crushed gravel. But then a person familiar with PHIUS design, the orientation of the windows—all that stuff is either ‘yes’
suggested replacing the gravel with perlite. “I never would have or ‘no’ in terms of meeting the requirements. For me, it’s well worth
thought of it,” he says. “It has an R-value of 3.5, it’s environmentally the extra effort.” GB
safe, and it was being made in [nearby] Bethlehem [Pa]. It comes in
8-inch bags. We used it, and our slab went from R-40 to R-75 at very
little cost. I never realized it could be that easy.” Key Components
Not everything was as cut and dried. Knowing that achieving the APPLIANCES: GE
Passive House designation depended on the home being airtight, BUILDING ENVELOPE: FPSF, TJI frame walls, raised heel engineered roof truss
Pedranti and Ciervo set out to make what amounted to an airtight CABINETS, SHELVES, MILLWORK: Starmark green certified
box. “Everything had to be perfect, especially since we had an CAULKS AND SEALANTS: Siga tapes
airtightness requirement of 0.6 ACH50,” Pedranti notes. “Your ‘box’ COUNTERTOPS: Green-certified granite
or envelope gives you a baseline. Then, every time you make a hole DOORS AND HARDWARE: Solid core birch veneer and Schlage
in the envelope—such as a window or door—you have an idea of EXTERIOR FINISHES: Paine board and batten
the amount of leakage.” FLOORING: Bamboo and tile
After accounting for the planned openings and sealing obvious HVAC/DUCTS: Mitsubishi 9KBTU
escape areas, the team used a blower door and a fog machine to detect INSULATION: 12-inch EPS and 8-inch perlite under slab, dense pack cellulose in
where any other leaks might be. Any leaks found were promptly walls, loose fill cellulose in ceiling
patched up with foam and vinyl tape. LANDSCAPING: N/A
“The first time were tested, we were certain we were going to LIGHTING: LED
pass,” Pedranti recalls. “When we failed, it was shocking. After all, PAINTS AND STAINS: Benjamin Moore Aura paint
it was a box!” PAVERS: Locally sourced bluestone
They never achieved better than 1.1 ACH50, far short of the PLUMBING/PLUMBING FIXTURES: N/A
minimum, he notes. RENEWABLE ENERGY SYSTEMS (SOLAR, WIND, ETC.): Wired for PV
On a whim, the team put a piece of polyurethane over a portion ROOF: Asphalt and metal
of the Oriented Strand Board (OSB) sheathing in use, reversed the SPECIALTY PRODUCTS: N/A
blower door and discovered that the problem was the OSB itself. STRUCTURAL COMPONENTS: TJI for walls and floors, raised heel engineered
“Sure enough, there was air leaking through the OSB,” Pedranti trusses for roof
says. “We were not happy. But we solved our problem by putting a TELECOMMUNICATIONS: N/A
membrane over the sheathing.” VENTILATION: RenewAir EV200 heat recovery ventilator
That reduced the home’s airtightness score to 0.34 ACH50—well WATER FILTRATION: N/A
under Passive House standards. The home’s overall HERS Index WATER HEATING: GE GeoSpring hot water heat pump
score is 28, a number that the homeowners are certain will improve WATER MANAGEMENT (INDOOR/OUTDOOR): N/A
as other energy-saving efforts come online. WINDOW COVERINGS: N/A
“I knew when I got into Passive House, there was a hard learning WINDOWS, SKYLIGHTS, PATIO DOORS: Intus triple-pane tilt/turn inswing

www.greenbuildermedia.com March/April 2018 GREEN BUILDER 51

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