A New Precedent for Fire Safety in High-Density Housing Across California

San Jose ADU Sets New Fire Safety Standard with Non-Combustible Construction

‍San Jose, CA —  Builtech Construction broke ground last week on an 850-square-foot ADU in San Jose. The ADU uses the ICF (Insulated Concrete Form) system and is the first in San Jose to be built to Type 1A standards, the highest fire-resistance classification under the International Building Code (IBC) and California Building Code (CBC). It marks a meaningful shift in how fire safety is being considered in California’s rapidly densifying neighborhoods: fire risk is no longer limited to WUI zones.

Since 2017, California has significantly expanded ADU development in response to statewide housing shortages. As a result, exposure density has increased, with more structures being built on the same lot and often separated by as little as four to ten feet. Several wildfire studies have found that structure-to-structure spacing is a key driver of fire spread, even outside traditional wildfire zones.

Rising Density Brings New Fire Risks

“Fire can originate elsewhere but travel far under extreme conditions, like with strong winds,” says Aaron Liu, a Certified Wildfire Mitigation Specialist (CWMS) and founder of Builtech Construction Group. “Higher density also means more human activities that can cause fires. For example, more families are hosting barbecues on the same lot during the summer.”

For homeowner Eric, the decision to build with a fire-resilient system was rooted in foresight rather than immediate necessity. “Wildfire risk is here to stay, and I didn’t want to wait for it to become real before taking it seriously,” he said. “If we’re building something new, it makes sense to build it stronger from the start and not have to rethink it later.”

Contrary to common perception, building with fire-resistant systems does not necessarily come at a premium. The cost of this ADU, approximately $350,000, is comparable to traditional wood-frame construction in the area. However, the ICF structure brings benefits beyond fire resistance.

ICF construction uses lightweight, hollow foam blocks that stack together like oversized Legos to form the exterior walls. After rebar is placed inside of the blocks, concrete is poured into the forms to create a solid, non-combustible core. Because the structure consists only of rebar, concrete, and foam, ICF walls are naturally fire-resistant, pest-proof, soundproof, seismic-resistant, and extremely energy-efficient, delivering up to 58% higher effective R-values than traditional wood framing.

The project is currently in the foundation trenching stage. Once the foundation is complete, the ICF exterior wall system can be erected in just over two weeks under typical conditions. The home will also incorporate a holistic non-combustible design approach, including fire-resistant windows, a metal roof structure, and fire-rated vents. Together, these measures work with ICF technology to eliminate vulnerabilities and deliver the resilient structure ready for today’s conditions.

About Builtech Construction Group

Builtech Construction Group is a California-based construction firm specializing in resilient, non-combustible building solutions for residential and commercial projects. Led by licensed contractor and Certified Wildfire Mitigation Specialist Aaron Liu, the company provides full-service design, engineering, permitting, and construction across the Bay Area and Los Angeles. With expertise spanning ICF (Insulated Concrete Form), 3D printing, cold-formed steel, and home hardening measures, Builtech aims to lead California’s transition toward safer, more sustainable homes and buildings.

Originally reported by Builtech Construction Group.