Project One.

A quest to build the world's largest Passive House

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.


All PHIUS-certified Passive Houses fully satisfy the requirements of these prestigious programs:

“Super excited about Project One, we believe passive and 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

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

Walker Home 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.”

Dave Brach

Brach Design

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 extreme efficiency through five strategies:

  1. Significant and continuous insulation, with few or no thermal bridges
  2. Robust air-tightness
  3. Balanced ventilation
  4. High-efficiency windows
  5. Minimal HVAC mechanicals

Beyond efficiency, Passive Houses excel in comfort, quality, health, safety, and durability. They are also more beneficial to the environment and have excellent economics. Learn more about the benefits of Passive Houses in “Why Certify?” below.

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 do the opposite: they prioritize function over form and often compromise good looks to achieve extreme performance numbers.

Project One proves you can have both: extreme performance in a house anyone would be proud to call home, custom built for a surprisingly economical price.

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.

As of September, 2023, the largest certified Passive House in America, 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, including rigorous evaluation and testing 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:

PHIUS certification includes Home Energy Rating System (HERS) as part of the third-party Residential Energy Services Network (RESNET) program

PHIUS certification satisfies all U.S. Department of Energy (DOE) Zero Energy Ready Home (ZERH) requirements

PHIUS certification earns the U.S. Environmental Protection Agency (EPA) Indoor airPLUS label

PHIUS certification satisfies all 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

(Net-Zero Energy)

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?

“PHIUS homes are the most luxurious, energy efficient, safe and resilient single-family dwellings on the planet.” (PHIUS website)

01 Efficiency

Certified Passive Houses are up to 85% more efficient than conventional homes. Energy costs go up over time, so the economic benefits of high efficiency grow year after year.

Once built into the structure of the home, the economic benefits of passive efficiency are permanent and increasing.

02 Energy Independence

Without any onsite energy production, Passive Houses are already close to net-zero, reducing dependence on off-site sources of energy. The addition of on-site solar or geothermal energy can bring total net-zero energy independence, potentially sufficient to also power electric vehicles.

03 Quality

From planning to execution, the extraordinary attention to detail and continuous inspection required to certify as a Passive House is unparalleled in construction, resulting in a carefully planned, expertly built structure of consistently high quality, from deep under the slab to the top of the roof.

04 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.

05 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.

Passive Houses manage moisture extremely well, limiting the risk for mold and other moisture-related problems. The air-tightness of Passive Houses greatly reduce the appearance of bugs and rodents.

06 Environment

Passive Houses are beneficial to the environment, greatly reducing dependence on fossil fuels.

07 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.

08 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.

09 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.

Like any significant home upgrade, Passive House improvements add to the value of the home; unlike other upgrades, however, they permanently lower monthly operating costs, becoming more cost-effective over time as external energy costs continue to increase.

Key Features and details

Under the Slab

6″ of R-6.5/inch closed-cell spray foam (ccSPF) and 1″ rigid EPS foam over interior footings (total: R-39)

Above-Grade Walls

Advanced framing with 2×6 studs at 24” on-center; 3” exterior EPS rigid foam (not XPS or polyiso, to avoid thermal drift); between studs: 2” ccSPF with 3.5” blown-in fiberglass (total: R-32)


Unvented attic; double-sheeted roof and cool-roof shingles; 4” ccSPF and 11” BIBS (total: R-62)

Below-Grade Walls

2″ ccSPF plus 3.5″ of R-4/inch insulation (total: R-27)


Low-E triple-pane glass windows, with thermally broken frames (U=0.13 to 0.14; SHGC=0.24 to 0.28)


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 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)


100% CFLs (Compact Fluorescent Lamps)


25 kW PV system


100% ENERGY STAR rated

Water Conservation

Low-flow faucets, dual-flush toilets, and drip irrigation

Special Construction

Project One is being constructed with advanced techniques and impeccable quality, from under the slab to the top of the roof.


Fully insulated continuous exterior envelope with zero thermal bridges


ThermalBuck installation for every window and exterior door


Geothermal heating and cooling with radiant


6” closed-cell spray foam under-slab


Advanced framing with 2x6 exterior studs 24” on center, “California Corners”, and pocket headers


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