Tetra-One: A Sustainable Architectural Innovation to Address California’s Housing and Wildfire Crises

Architectural Innovation Confronts California’s Crises

In a backyard in La Jolla, a unique architectural structure emerges, reminiscent of origami art, with sharp angles reflecting the Californian sun. Yet, this building is not merely a modern accessory dwelling unit (ADU); it is an attempt to address one of the state’s most pressing issues: the escalating housing crisis and the threat of wildfires.

Background of the Concept

In 2021, Daniel Lopez-Perez and Celine Vargas founded Polyhaus after witnessing firsthand the devastating wildfires consuming vast areas of California year after year.
Drawing on their experience as architects, they reached a clear conclusion:

• Traditional wood-framed homes have become increasingly vulnerable to fire.
• Conventional construction methods are slow and inefficient in addressing new challenges.

A Fundamental Question

From this reality arose a simple yet pivotal question:
Can homes be architecturally beautiful while also being fire-resistant and safer?

Wood as a Barrier Against Fire

The solution came through the use of Cross-Laminated Timber (CLT) panels sourced from restoration projects in the Colville National Forest in Washington State.
These panels are not used in the conventional way; instead, they undergo precise robotic manufacturing processes that ensure:

• Assembly of structures without any air gaps.
• Fire resistance three to five times greater than traditional wood.

Integrated Protective Layers

To further enhance safety, the wooden panels are clad with insulating metal sheets, providing multiple layers of protection while maintaining high energy efficiency, making the building both practical and economical.

A Practical Model in the Backyard

The proof of concept stands in the project founders’ backyard, where a 540-square-foot unit was built:

• 440 square feet on the ground floor.
• 100 square feet as an upper mezzanine.

Despite its modest size, the smart design makes the unit feel spacious, featuring:

• A fully equipped kitchen.
• A bathroom.
• A living area and extra space.
• A comfortable upper bedroom.

A Design That Rethinks Housing

The sharply pitched roof, inspired by A-frame design, adds a significant advantage: it doubles the interior space while keeping the land footprint minimal.

Unprecedented Construction Speed

What sets the Tetra-One apart is not limited to its high fire resistance; it also extends to its standard assembly time.
Thanks to advanced prefabrication technologies, the unit can be fully assembled in just three days, an almost impossible timeframe in California’s traditionally slow construction environment.
These techniques were originally designed for large-scale commercial projects but have been adapted for residential use, making them more aligned with individual needs.

Sustainability Beyond Protection

The story does not stop at fire protection. The Tetra-One philosophy embraces a broader approach that links environmental sustainability with modern housing:

• Using timber sourced from forest restoration makes each unit part of an ecological balance process.
• This approach helps prevent wildfires at their roots through healthy forest management.
• At the same time, it provides high-quality building materials that improve over time thanks to organized and monitored harvesting.

An Affordable Option in a Challenging Market

The Tetra-One positions itself as a relatively accessible entry point toward homeownership, priced at $300,000, compared to the median cost of constructing an accessory dwelling unit (ADU) in San Diego, which often exceeds this figure.
Yet, most traditional construction remains less capable of meeting these challenges, whether in terms of fire resistance or the rapid assembly offered by the Tetra-One.

Critical Timing and the Housing Crisis

This innovation arrives at a particularly critical moment. California faces what can be described as a “perfect storm”:

• A severe housing shortage.
• Increasing wildfire risks.
• The impacts of climate change on the environment and communities.

Conventional solutions appear inadequate in a reality where entire neighborhoods can vanish overnight during fire seasons.

Toward a Sustainable and Practical Future

The Tetra-One charts a different path for the future. Polyhaus has now expanded to offer designs ranging from the original ADU to homes up to 2,500 square feet, indicating that the Tetra-One was only the beginning.
With mounting climate challenges and rising housing costs, this architectural structure in La Jolla may not just be an innovative design, it could provide a glimpse into how we might build homes that protect both people and the planet.

✦ ArchUp Editorial Insight

The Tetra-One project demonstrates clear innovation in integrating sustainability with modern architectural design, drawing attention for its construction speed, fire resistance, and energy efficiency. However, several notable challenges remain; the project may face constraints related to the limited space of the core units, the upfront cost that may not be accessible to everyone, and the need for careful monitoring to ensure the long-term effectiveness of sustainable materials. Moreover, the heavy reliance on prefabrication technology raises questions about the model’s replicability on a larger scale or in regions with different climatic and environmental conditions. In this way, the project offers an intriguing model but one that requires caution when considering its generalization or reliance as a comprehensive solution to the housing crisis and wildfire threats.

Prepared by the ArchUp Editorial Team

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