How Wildfire-Ready Homes Can Truly Live Well, Too

Editor’s Note: Graham Irwin presented on this topic at PhiusCon 2025, the annual conference of the Passive House Institute US (PHIUS) that took place in Milwaukee this October. We asked him to highlight his approach here to share key insights on wildfire-resilient, high-performance home design with our readers.

At Essential Habitat Architecture, we design high-performance homes for Californians who want to live more comfortably, sustainably, and securely. Our work begins with a guiding principle: every design decision should deliver multiple benefits.

Phase One: Living Through Wildfire

Beyond the Code

The first phase is ensuring that, when wildfire strikes, the home itself can endure it. Fire hardening is the foundation here. California’s codes provide the baseline—ignition-resistant materials, ember-resistant assemblies, and one pane of tempered glazing—but we don’t stop there.

We view every part of the building envelope as part of an integrated defense system. We design ignition-resistant, ember-proof, unvented assemblies, specify fire-resistant, high-performance windows with fully tempered glazing, and plan defensible landscapes that add beauty as well as safety.

These measures are essential to protect life and property, but they’re also like insurance or seismic reinforcement: valuable for what they prevent, not for what they deliver daily. The next step in our framework adds measures that can improve life for many people on a regular basis.

Phase Two: Living With Wildfire

Even if a home never faces direct flames, its occupants will almost certainly experience wildfire's secondary impacts: smoke, poor air quality, and power interruptions caused by grid safety shutoffs. Designing for this phase means planning for the realities of life in California's new normal: living with wildfire events.

Airtight Equals Smoke-Tight

Clean indoor air starts with control of what comes in and what goes out. But the typical leaky construction makes that nearly impossible.

Our homes combine rigorous air sealing, balanced ventilation, and HEPA filtration for smoke events, maintaining clean, healthy air even when outside conditions are hazardous.

Resilient Efficiency

Airtightness and insulation also yield exceptional energy efficiency. A high-performance home requires far less energy to heat and cool and can maintain comfortable indoor temperatures much longer during outages.

Backup systems like batteries or generators can run these homes longer and more effectively because they simply demand less. As I tell clients: resilience and comfort are two sides of the same coin.

Phase Three: Living Well

The most rewarding phase is Living Well, where safety and performance converge into pure comfort and ease, improving life on a daily basis (in addition to the benefits above).

Using detailed energy modeling, we fine-tune every design to find the sweet spot: optimal efficiency and comfort without waste. Our goal is to meet or exceed passive building (Passive House) standards, creating homes that are inherently comfortable, quiet, and healthy.

These homes maintain steady temperatures, filtered air, and peace of mind every day, including during power outages or smoke events. Living Well is when the technology fades into the background and the home simply works.

While this level of performance requires some additional investment upfront, our holistic process finds the most cost-effective path to excellence, ensuring that every dollar spent delivers maximum benefit.

Optimized Design in Action

To illustrate the difference design makes, consider three wall assemblies—all with equivalent one-hour fire ratings: 

The differences in detailing and materials may seem minor, but their performance outcomes are dramatically different.

The Living Well assembly (right) is part of a whole-building system that maximizes fire resilience, efficiency, and comfort.

Project Highlight: A Fire-Resilient High-Performance Home

We designed “The Altadena,” a 2,500-square-foot home, to aid rebuilding after the Los Angeles wildfires. It includes three bedrooms and two bathrooms upstairs, plus an accessible bedroom suite/ADU, great room, and a half-bath on the ground floor.

The home blends modern sensibility with the warmth and openness characteristic of the area’s historic architecture. Its efficient two-story form provides excellent daylight and views while maintaining privacy on narrow lots from nearby homes on either side.

Exterior walls use two-by-four framing plus a continuous 1 1/2-inch layer of exterior mineral wool insulation that wraps over the roof and under the slab. Double gypsum board layers on the interior add both enhanced fire resistance and thermal mass for comfort and acoustics. The result: assemblies exceeding one-hour fire ratings and providing exceptional thermal and sound performance.

High-performance, triple-pane tempered windows and doors enhance safety and comfort, while exterior wood accents are strategically located beyond the thermal envelope to preserve the continuous, insulated, fire-resistant shell.

A stone-clad patio wraps around the building, creating defensible space while echoing the fieldstone foundations of the area’s historic homes.

The result is a home that’s quiet, healthy, and durable—resilient not only to wildfire but to the broader challenges of California’s future.

This Sunnyvale remodel and retrofit project of ours perfectly demonstrates the Living Well philosophy. Once a dark, drafty 1950s tract house, it’s now an open, efficient, and healthy all-electric home.

Designing for a New Kind of Resilience

Designing for wildfire resilience isn’t just about surviving disasters, it’s about thriving in a changing climate.

In our practice, we see fire safety, energy efficiency, and everyday comfort as deeply interconnected goals. When thoughtfully integrated, each reinforces the others, producing homes that are safer, healthier, and more sustainable—not just in emergencies, but every day.

Living Through wildfire, Living With wildfire, and Living Well aren’t separate objectives; they’re parts of one unified vision: a future where our homes protect, sustain, and enrich life, no matter what challenges surround them.