The World's Largest Passive House
What is a Passive House?
Imagine a building that's not just efficient but ultra-efficient. A certified Passive House, up to 85% more efficient than a typical building, brings this vision to life. Certified by Passive House Institute U.S. ( PHIUS ) in the United States or Passive House International ( PHI ) internationally, these homes can be heated by the equivalent of a single hair dryer.
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.
Project One is the first in the Designer Passive House series from Cross Construction of certifiable passive and near-passive homes that are both beautiful and economical.
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Project One: This home is still under construction.
Initial Animated Rendering
Luxury & Efficiency
It’s important to note that a luxury home can be passive and energy efficient. Cross emphasizes that you don’t have to sacrifice your luxury dream to have a more efficient and environmentally friendly home. Project One is a testament to our commitment to balance. It's not about extreme performance or good looks but a harmonious blend of both. This house meets and exceeds expectations while being remarkably economical to build.
Early Build Progress
Passive House
verification
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 been successfully certified with Phius in the United States, and only ten are 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 challenging 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.
Phius homes are the most luxurious, energy efficient, safe and resilient single-family dwellings on the planet.
Thermal Flooring
Why Certify?
01 )
Efficiency
Certified Passive Houses are up to 85% more efficient than conventional homes. As energy costs increase over time, the economic benefits of high efficiency grow yearly.
Once built into the home's structure, the economic benefits of certified-level passive efficiency are permanent.
02 )
Energy Independence
Without on-site energy production, Passive Houses are already close to net zero, significantly reducing dependence on off-site energy sources. Additional on-site solar or geothermal energy can bring total net-zero energy independence, potentially sufficient to power both a home and electric vehicles
03 )
Comfort
Passive houses more easily stay warm in the winter and cool in the summer and have fewer hot and cold spots than typical homes, enjoying temperatures evenly distributed throughout the structure.
04 )
Health
EPA Indoor airPLUScertification ensures optimal, healthy indoor air. Passive houses are actively mechanically ventilated and filtered, keeping pollen, smoke, and other pollutants outside where they belong, resulting in healthier indoor air than conventional homes.
05 )
Environment
Passive houses benefit the environment by significantly reducing dependence on fossil fuels
06 )
Safety
Phius-certified buildings undergo a rigorous quality control process, ensuring safety for the inhabitants and the environment. From the sturdy construction to the purified indoor air, Passive Houses are the safest around.
07 )
Durability
The holistic design of Phius buildings makes them uniquely built for the long haul. They have been proven more resilient to natural disasters like wildfires, extreme heat, and cold events.
08 )
Resale
Passive houses can cost 3-10% more to build than typical, code-minimum houses. Still, they have been shown in some cases to command a
9% price premium upon resale, recouping the initial investment.
Like other home upgrades, Passive House improvements add to the home's value; unlike other upgrades, however, they permanently lower monthly operating costs, becoming more cost-effective over time as external energy costs continue to increase.
State of the Art Insulation
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-3
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 the interior (R-22) for R-32 total
Windows
Low-E triple, extreme 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.
Water Heating
119-gallon high-efficiency heat pump water heater (135 gallon UFHR first hour) with a 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.
Enhanced Foundation Insulation Supports Even Temperatures Year Round
Project One is being constructed with advanced techniques & impeccable quality, from under the slab to the top of the roof.
01 )
Insulation
Fully insulated continuous exterior envelope with zero thermal bridges..
02 )
Windows
ThermalBuck installation for every window and exterior door
04 )
Foundation
6” closed-cell spray foam under-slab
06 )
Roof
Double-sheeted to provide whole-roof ventilation, keeping shingles cool in the summer and preventing ice dams in the winter.
07 )
"Awesome" attics
Designer Passive Houses like Project One condition the attic by amply insulating the roof instead of the attic floor, increasing building efficiency and adding usable space.
(Learn more at BuildingScience.com)HERS Index
Co-Requisite Programs
All PHIUS-certified Passive Houses fully satisfy the requirements of these prestigious programs:
“ They are top-notch professionals, fair pricing, very creative, they own their mistakes, and their attention to detail makes them quality craftsmen. It was a great experience working with them. "
RESNET
Residential Energy
Services Network
PHIUS certification includes Home Energy Rating System (HERS) as part of the third-party Residential Energy Services Network (RESNET) program
ZERO
Energy Ready Home
U.S. Department of Energy
PHIUS certification satisfies all U.S. Department of Energy (DOE) Zero Energy Ready Home (ZERH) requirements
EPA Indoor
airPLUS
PHIUS certification earns the U.S. Environmental Protection Agency (EPA) Indoor airPLUS label
ENERGY STAR
PHIUS certification satisfies all U.S. Environmental Protection Agency (EPA) ENERGY STAR requirements
IECC 2012
Enclosure
HERS
70-80
IECC
2012
HVAC Q1
w/WHV
Water
Management
Independent HERS
Verification
IECC 2012
Enclosure
HERS
60-70
E
STAR V3
HVAC Q1
w/WHV
Water
Management
Independent HERS
Verification
IECC 2012
Enclosure
HERS
50-60
ENERGY
STAR V3.1
SOLAR READY
(Depends on climate)
Eff. Comps. & H20
Distrib.
EPA Indoor
airPLUS V1
Ducts in
Condit. Space
HVAC Q1
w/WHV
Water
Management
Independent HERS
Verification
IECC 2015/18
Encl./ES Win.
HERS
35-45
ZERH
Electrification
Readiness
Electric Vehicle
Readiness
Balanced Ventilation
HRV/ERV
SOLAR READY
(Always)
Eff. Comps. & H20
Distrib.
EPA Indoor
airPLUS V1
Ducts in
Condit. Space
Micro-load
HVAC Q1
Water
Management
Independent HERS
Verification
Ultra-Efficient
Enclosure
HERS
30-40
PHIUS
CORE
Renewable Energy to
Get to Zero
Electrification
Readiness
Electric Vehicle
Readiness
Balanced Ventilation
HRV/ERV
SOLAR READY
(Always)
Eff. Comps. & H20
Distrib.
EPA Indoor
airPLUS V1
Ducts in
Condit. Space
Micro-load
HVAC Q1
Water
Management
Independent HERS
Verification
Ultra-Efficient
Enclosure
HERS
40
PHIUS
Zero
Staircase to ZERO
Project One Boasts PHIUS Core Level Ratings
( Net-Zero Energy )
VIEW IMAGE
“ I’m super excited about Project One, we believe passive & near-passive homes are the future. This extraordinary home is the first of many beautiful and economical custom Passive Houses we’ll be building in Utah in the Designer Passive House series.
Alex Cross
Cross Construction
Jamie Walker
Walker Home Design
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!
Dave Brach
Brach Design
We jumped on the new passive house movement early, in 2008. We are Utah’s first and most experienced Certified Passive House Consultants ( CHPCs ) and Passive House designers, and are thrilled to be a part of Project One.
Project One Partners
We believe passive homes are the future.
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