Project One.
A quest to build the world's largest Passive House
CO-REQUISITE PROGRAMS
All PHIUS-certified Passive Houses fully satisfy the requirements of these prestigious programs:
Alex Cross
Cross Construction
Project Partners
“As Utah’s Best of State award winning home designer in 2023 and most of the last decade, we are honored to have created the plans for Project One, which will be the largest certified passive house in the World!”
Jamie Walker
Dave Brach
- Project Data
- Start date: July, 2023
- Est. completion: July, 2024
- Total Conditioned Space: 15,990 sf
- Living Space: 13,349 sf
- Conditioned Garage: 1,871 sf
- Conditioned Storage & Attic: 770 sf
- Performance Data
- (Target / Achieved)
- Air-Tightness: 0.6 ACH50 / TBD
- Total Energy Demand:45,000 BTUs / TBD
- Solar Generation: TBD / TBD
- R-Values Required/Achieved:
- Under-Slab: R-36 / TBD
- Ground Wall: R-34 / TBD
- Above-Grade Wall: R-34 / TBD
- Roof: R-60 / TBD
- Windows: R-7 / R-7.1 (0.14 avg. U-factor)
- Est. passive house annual energy cost: $
- Est. typical annual energy cost: $$$$
What is a "Passive House" ?
A certified Passive House is an ultra-efficient building – up to 85% more efficient than a typical building – which has been certified by Passive House Institute U.S. (PHIUS) in the United States or Passive House International (PHI) internationally. Some full-sized Passive Houses are capable of being heated by the equivalent of a single hair dryer. (Learn more Here.)
Passive Houses achieve this high efficiency through five strategies:
- Significant and continuous insulation (few or no thermal bridges)
- Robust air-tightness
- Balanced ventilation
- High-efficiency windows
- Minimal HVAC mechanicals.
Project One: Passive House performance, good looks, economical to build.
Conventional homes prioritize form over function, resulting in good-looking homes that barely meet minimum code requirements. Passive Houses typically do the opposite, prioritizing function over form, often compromising good looks in the pursuit of extreme performance numbers.
Project One proves you can have both: extreme performance in a house anyone would be proud to call home, while being remarkably economical to build.
Passive House certification is hard. Very hard.
There are two very high competing standards for Passive Houses: PHI and Phius. As of September, 2023, only 224 single-family homes have successfully certified with Phius in the United States, and only 10 in Utah; PHI has certified 1,153 homes internationally with 45 in the U.S. and none in Utah.
Currently the largest certified Passive House in America, by PHI, is just over 7,700 square feet, about half the size of Project One. Project One will certify through Phius.
Phius certification requires proving the attainment of hundreds of difficult performance standards and criteria, and only after satisfying a rigorous evaluation and testing process before, during, and after construction. Project testing and inspections are conducted by independent RESNET HERS Raters, and help assure Phius and the project teams that the home performs as designed.
One Certification to rule them all:
Include Home Energy Rating System (HERS) as part of the third-party Residential Energy Services Network (RESNET) program
Include U.S. Department of Energy (DOE) Zero Energy Ready Home (ZERH) requirements
Include the U.S. Environmental Protection Agency (EPA) Indoor airPLUS label
Include U.S. Environmental Protection Agency (EPA) ENERGY STAR requirements
Hers® Index
A certified Home Energy Rater assesses the energy efficiency of a home, assigning it a relative performance score. The lower the number, the more energy efficient the home. A typical home built to 2006 energy efficiency standards scores 100 on the HERS® Index.
Staircase to zero
The Phius standards build upon 3rd party programs such as ENERGY STAR, EPA Indoor airPLUS, and DOE Zero Energy Ready Home. These well-respected programs provide a baseline quality framework for design and construction inspection.
Why Certify?
01 Efficiency
02 Energy Independence
03 Comfort
04 Health
EPA Indoor airPLUS certification ensures optimal, healthy indoor air. Passive houses are actively mechanically ventilated and filtered, keeping pollen, smoke and other pollutants outside where they belong and resulting in healthier indoor air than conventional homes.
05 Environment
Passive Houses are beneficial to the environment, greatly reducing dependence on fossil fuels.
06 Safety
Phius-certified buildings go through a rigorous quality control process, ensuring safety for the inhabitants and the environment. From sturdy construction to purified indoor air, Passibe Houses are the safest around.
07 Durability
The holistic design of Phius buildings make them uniquely built for the long haul. Phius buildings have been proven to be more resilient in the event of natural disasters, such as wildfires and extreme heat and cold events.
08 Resale
Passive houses can cost from 3-10% more to build than typical, code-minimum houses, but have shown in some cases to command a 9% price premium upon resale, recouping the initial investment.
Key Features and details
Above-Grade Walls
Advanced framing with 2×6 studs at 24” on-center; 4” exterior rigid EPS foam (not XPS or polyiso, to avoid thermal drift); interior/between studs: 2” closed-cell spray foam (ccSPF) with 3.5” blown-in fiberglass (total: R-38)
Roof
Unvented attic; exterior: 4” EPS rigid foam, with double-sheeted roof and cool-roof shingles; interior: 3” ccSPF and 12” BIBS (total R-60)
Below-Grade Walls
R-10 exterior closed-cell rigid insulation plus two R-11 draped batts on interior (R-22) for R-32 total
Windows
Low-E triple-pane glass windows, with thermally broken frames (U=0.14 to 0.16; SHGC=0.19 to 0.21)
Ventilation
Two ERV (Energy Recovery Ventilation) units provide continuous mechanical filtering of all indoor air, at a rate of 6 changes per hour
HVAC
Geothermal/Ground Source Heat Pump (? HSPF and ? SEER) for heating and cooling, radiant in the basement
Water Heating
119-gallon high-efficiency heat pump water heater (135 gallon UFHR first hour) with glass-lined tank, uses environmentally friendly CO₂ refrigerant (R744),
Lighting
100% CFLs (Compact Fluorescent Lamps)
Solar
25 kW PV system
Appliances
100% ENERGY STAR rated
Water Conservation
Low-flow faucets, dual-flush toilets, and drip irrigation
Special Construction
Insulation
Fully insulated continuous exterior envelope with zero thermal bridges
Windows
ThermalBuck installation for every window and exterior door
HVAC
Geothermal heating and cooling with radiant
Foundation
6” closed-cell spray foam under-slab
Framing
Advanced framing with 2x6 exterior studs 24” on center, “California Corners”, and pocket headers
Roof
Double-sheeted to provide whole-roof ventilation, keeping shingles cool in the summer and preventing ice dams in the winter
“Awesome” attics (not “crappy”)
Designer Passive Houses like Project One condition the attic by amply insulating the roof instead of the floor of the attic, increasing building efficiency and adding usable space. (Learn more at BuildingScience.com)
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