In a La Jolla backyard, a geometric structure rises like an origami masterpiece, its sharp angles catching the California sun. This isn’t just another trendy ADU. The Polyhaus Tetra-One represents something far more significant: a potential solution to two of California’s most pressing crises.
Daniel Lopez-Perez and Celine Vargas founded Polyhaus in 2021 after watching their home state burn year after year. As architects, they understood that traditional stick-built homes were becoming increasingly vulnerable to California’s intensifying wildfire seasons. Their frustration with slow, inefficient construction methods led them to ask a simple question: What if homes could be both beautiful and bulletproof against fire?
Designer: Polyhaus
The answer came in the form of Cross-Laminated Timber panels sourced from Washington’s Colville National Forest restoration projects. These CLT panels undergo robotic fabrication, creating structures with zero air gaps that are three to five times more fire-resistant than conventional wood construction. Wrapped in insulated metal panels, the Tetra-One creates multiple layers of protection while maintaining exceptional energy performance.
The proof of concept sits in their own backyard. The 540-square-foot unit features 440 square feet on the ground floor with a 100-square-foot mezzanine loft above. Despite its compact footprint, the space feels remarkably open, housing a full kitchen, bathroom, living area, bonus space, and cozy sleeping loft. The sharply pitched roof, reminiscent of an A-frame, maximizes interior volume while minimizing land use.
What sets the Tetra-One apart isn’t just its fire resistance. The entire structure can be assembled in three days, a timeline that seems impossible in California’s notoriously slow construction environment. This speed comes from advanced prefabrication techniques typically reserved for large-scale commercial projects, now scaled down for residential use.
The sustainability story runs deeper than fire resistance. By using timber from forest restoration projects, each Tetra-One creates a direct link between healthy forests and sustainable housing. This approach addresses wildfire prevention at its source while providing building materials that actually improve with controlled harvesting.
At $300,000, the Tetra-One positions itself as an accessible entry point into homeownership in California’s brutal market. For comparison, the median ADU construction cost in San Diego often exceeds this figure, yet most lack Tetra-One’s fire resistance and rapid construction timeline.
The timing couldn’t be more critical. California faces a perfect storm of housing shortage, wildfire risk, and climate change impacts. Traditional solutions feel inadequate when neighborhoods can disappear overnight in fire seasons. The Tetra-One offers a different path forward. Polyhaus now offers designs ranging from the original ADU up to 2,500 square feet, suggesting the Tetra-One was just the beginning. As climate challenges intensify and housing costs soar, this geometric structure in La Jolla might represent more than innovative design. It could be a glimpse into how we’ll build homes that protect both people and planet.
The post This Fire-Resistant ADU Could Reshape California Housing first appeared on Yanko Design.