Benefits of Unvented Attics

California faces rising wildfire threats and high energy costs, and a recent Capitol Weekly article argues that one practical solution is encouraging unvented attics in new homes. Unlike traditional vented attics—which allow outside air, heat, and embers to enter—unvented attics create a sealed, insulated space that improves energy efficiency and boosts wildfire resilience. The author highlights real-world performance, including a home that survived a major fire thanks to its sealed attic design, and calls on state agencies to update building codes and offer incentives that make unvented attics easier to adopt.

To explore the full argument and proposed policy changes, read the article here: https://capitolweekly.net/california-should-incentivize-homes-with-unvented-attics/

What is an Unvented Attic?

An unvented attic is one where the attic space is brought inside the home’s “thermal envelope” (the insulated, sealed barrier between the interior and outside). Insulation is applied at the roof-line rather than the ceiling and the attic is sealed from outside air infiltration.

Two Major Benefits of Unvented Attics

• Wildfire resilience: Vented attics provide entry points—vents equal openings—for embers, heat, smoke. For example, California’s building code allows one square foot of vent per 150 square feet of attic space, so a 1,000 sq ft attic might have ~7 sq ft of vent openings. That’s a potential weakness in a fire scenario.

• Energy efficiency & cost savings: By keeping the attic inside the conditioned space, HVAC duct-work stays within the insulated envelope and the building performs better. According to the piece, the California Energy Commission reports around an 18 % improvement in heating/AC efficiency from such assemblies.

A Step Ahead with Quadrant

At Quadrant Performance Materials, we’re proud to see EnviroSeal spray foam continue to open new possibilities for builders. By combining fire safety, efficiency, and durability in one product, it’s helping raise the bar for what insulation can do. Contact us to learn more about how we can help you!