A quest to build the world's largest Passive House
All PHIUS-certified Passive Houses fully satisfy the requirements of these prestigious programs:
“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!”
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.
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:
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.
02 Energy Independence
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.
Passive Houses are beneficial to the environment, greatly reducing dependence on fossil fuels.
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.
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.
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
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)
Unvented attic; exterior: 4” EPS rigid foam, with double-sheeted roof and cool-roof shingles; interior: 3” ccSPF and 12” BIBS (total R-60)
R-10 exterior closed-cell rigid insulation plus two R-11 draped batts on interior (R-22) for R-32 total
Low-E triple-pane glass windows, with thermally broken frames (U=0.14 to 0.16; SHGC=0.19 to 0.21)
Two ERV (Energy Recovery Ventilation) units provide continuous mechanical filtering of all indoor air, at a rate of 6 changes per hour
Geothermal/Ground Source Heat Pump (? HSPF and ? SEER) for heating and cooling, radiant in the basement
119-gallon high-efficiency heat pump water heater (135 gallon UFHR first hour) with glass-lined tank, uses environmentally friendly CO₂ refrigerant (R744),
100% CFLs (Compact Fluorescent Lamps)
25 kW PV system
100% ENERGY STAR rated
Low-flow faucets, dual-flush toilets, and drip irrigation