The World's Largest
Single-family, PHIUS-certified, Passive House Home
15118 South 2815 West, Bluffdale, UT
Offered at $6,500,000
Winner of the prestigious People’s Choice Award for the 2025 Salt Lake Parade of Homes - Built by Cross Construction
Project One is the largest single-family, PHIUS-certified, Passive House home in the world, setting a new standard for sustainable luxury living. Designed and built by Cross Construction, this 14,953 sq. ft. (1390 sq. m.) residence in Bluffdale, Utah integrates advanced building science with refined aesthetics. Achieving PHIUS CORE 2021, DOE Zero Energy Ready Home, and EPA Indoor airPLUS certifications, the home demonstrates that ultra-efficiency and high-end design can coexist. Through a tightly coordinated system of insulation, geothermal heating, solar energy, and high-performance ventilation, Project One achieved a HERS score of 30 and net-zero readiness.
This 15,000 square foot architectural masterpiece combines modern sophistication, comfort, and creativity as the largest certified single-family Passive House in the world.
Set on a beautifully landscaped one-acre estate, it features 8 bedrooms, 10 bathrooms, and three kitchens, including a private two-bedroom guest apartment. Designed for entertaining large groups, indoor/outdoor spaces abound with comfortable seating for well over 50 people. Every detail reflects thoughtful design and craftsmanship, from the gourmet kitchen with walnut cabinetry and dual ten-foot islands to the resort-style pool, racquetball court, and inviting Hobbit room that brings a sense of wonder to the home.
The twenty-seat theater is an entertainment masterpiece with a twenty-foot screen, a bright commercial-grade projector, and a fully immersive Dolby Atmos sound system powered by nineteen speakers and four subwoofers, creating an experience that surpasses most professional cinemas.
Powered by geothermal and solar energy with a HERS rating of 30, triple pane Alpen windows, and continuous filtered fresh air, the home provides quiet, draft-free comfort in every season, creating a living environment unlike any other in Utah.
The Location
15118 South 2815 West, Bluffdale, Utah, 84065
Nestled in the heart of Bluffdale, Project One offers a rare blend of open space, mountain views, and convenient access to the Salt Lake Valley and Utah County tech corridor. Bluffdale is known for its quieter residential setting, larger homesites, and proximity to nature—while still being just minutes from major commuter routes.
Located near Redwood Road and Bangerter Highway, the property provides easy connectivity to both Salt Lake City to the north and Lehi to the south, making it ideal for professionals working in the Silicon Slopes tech hub. Residents enjoy access to nearby shopping, dining, and daily conveniences while maintaining a sense of retreat from the urban core.