These $300K Prefab Cabins Are Designed to Withstand Wildfires

Welcome to Prefab Profiles, an ongoing series of interviews with people transforming how we build houses. From prefab tiny houses and modular cabin kits to entire homes ready to ship, their projects represent some of the best ideas in the industry. Do you know a prefab brand that should be on our radar? Get in touch!

Around 2009, Daniel Lopez-Perez and his wife, Celine Vargas, had started looking for a way to circumvent the limitations of conventional construction. Stick-built homes were slow to build, they thought, and often weren’t designed to withstand fires, increasingly a risk in their home state of California. So they asked, "What building technology can we leverage to build beautiful housing that is more resilient in a smarter, faster way?"

More than 10 years later, in 2021, they founded prefab company Polyhaus, and soon after built the first model in their own backyard in La Jolla, a 540-square-foot ADU that served as proof of concept for fire-resistant homes that can be built quickly and efficiently. Now the company is offering designs ranging in size from that first ADU up to 2,500 square feet. Here, Lopez-Perez and Vargas share their vision for bringing more Polyhaus units to California and beyond.

What’s the most exciting project you’ve realized to date?

We built the first model, the 540-square-foot Tetra-One, as an ADU in the backyard of our 1962 home in La Jolla. It showed that leveraging advanced engineering and technology used in large-scale projects for small-scale housing works to accomplish many goals: It can generate beautiful residential spaces; maximize living space volume with minimal land use; reduce building times; produce fire-resilient homes; and be cost-competitive.

Our favorite aspects of this design its spatial and material qualities. Natural light, cross breezes, soft wood grain, and ample open space create a deep sense of harmony and comfort that is felt as soon as you step inside.

What does your base model cost and what does that pricing include?

The Tetra-One asks $300,000, depending on site conditions and finishes. The Tetra-Two (980 square feet) and Tetra-Three (1,165 square feet) are priced at $400,000, also depending on site conditions and finishes. These prices include everything: design, engineering, permitting, unit fabrication, delivery, assembly, and construction costs (foundations, utility hookups, and all trades including electrical, plumbing, HVAC, and finishes).

What qualities make your tiny home stand apart from the rest?

Simply, our system is meant to maximize resources, including time, space, and environment. It also aims to reduce time, labor, and opportunity costs. Units are built with panels CNCed out of cross-laminated timber (CLT). The Tetra-One has 64 panels and can be assembled in just a few days, much like a puzzle. Our method leverages the geometric efficiency of truncated polyhedrons, maximizing living space within a minimal land footprint. These designs also enhance orientation and use-flexibility due to their three-dimensional symmetry.

The CLT is made from Douglas fir that’s sourced from restoration projects in the Colville Forest, led by our partners Vaagen Timbers in Washington. We are proud to offer a housing solution that builds a direct link between the health of our national forests and our housing production in California.

In addition, the CLT panels offer a high degree of wildfire-resilience given that they are robotically fabricated and leave no air gaps that would otherwise feed a fire, offering burn-rate levels seven to ten times slower than the rate of conventional stick-frame construction. The CLT panels are in turn wrapped by high-performing insulated metal panels that offer their own unique fire resistance. Finally, the aerodynamic form that results from the model’s shape also minimizes areas vulnerable to fire.

What aspects of the design can a client customize?

Customers can choose from a series of colors for the metal envelope and a selection of finishes for the interiors.

Where is the tiny home currently available?

We can ship anywhere within the continental U.S.

Is your design currently pre-permitted in any U.S. municipalities?

The Tetra-One is pre-permitted in San Diego County.

Are there plans to expand?

We are currently focused on scaling access nationally with longer-term plans to expand internationally.

How long can a client expect the process to take after they put down a deposit?

With our rapid construction system, and depending on the model and site conditions, we estimate an approximate six-month following timeline: In the first week, Polyhaus assesses the viability of your property. During weeks two and three, partner contractors provide a detailed bid (working off a pre-negotiated starting price). Weeks four to seven, Polyhaus processes your permits (referencing already approved permits). From two to six months, your unit is built. Then you move in!

What aspects of an install do you manage?

We offer a simplified three-stage contract with individual clients to oversee all preconstruction services: schematic design (site feasibility), design development (full project scope) and construction development (full permit and construction bidding set). After the project is permitted, we will work closely alongside a certified local general contractor to ensure the unit is built and delivered to meet the Polyhaus standard.

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