Blown-In Fiberglass Insulation

Blown-in fiberglass insulation is one of the most durable insulation types available and can last 20–30 years or more under normal conditions. Unlike cellulose, fiberglass does not decompose or attract pests as a food source. However, its lifespan can be shortened by moisture intrusion, rodent activity, or physical disturbance during renovations. FairPrice recommends a professional inspection every 10–15 years to ensure your insulation is still performing at its rated R-value. If you've had any pest issues or water damage, an earlier inspection is strongly advised.

The cost of blown-in fiberglass insulation varies based on the size of the area being insulated, the current insulation levels, and whether any remediation (such as old insulation removal or rodent damage cleanup) is needed. Most Bay Area attic insulation projects range from $1,500 to $4,500 depending on square footage and depth required. FairPrice provides free, no-obligation estimates so you'll know the exact cost before any work begins. We also offer financing options and seasonal coupons to help make the investment more manageable.

Both are effective options, but blown-in fiberglass has several advantages for Bay Area homeowners. Fiberglass is inorganic, meaning it does not absorb moisture, decompose, or serve as a food source for pests — a significant benefit in California's climate where moisture and rodents are common concerns. Fiberglass also maintains its R-value more consistently over time and does not settle as dramatically as cellulose. Cellulose, made from recycled paper, can be a good eco-friendly option but requires more careful moisture management. FairPrice can help you evaluate which product is best suited for your specific home and situation.

Not always. In many cases, blown-in fiberglass can be added directly on top of existing insulation to boost R-value — this is a common and cost-effective approach for attic upgrades. However, old insulation must be removed if it has been contaminated by rodents, affected by mold or moisture, or if it contains hazardous materials such as asbestos (common in homes built before 1980). FairPrice will inspect your existing insulation during the free estimate and advise you on the best approach for your home.

Yes — significantly. According to the U.S. Department of Energy, adding insulation to an under-insulated home can reduce heating and cooling costs by 10–20% or more. Many Bay Area homes, particularly those built before 1990, have attic insulation well below current California Title 24 requirements. Upgrading to the recommended R-49 in your attic can make a noticeable difference in both comfort and monthly utility costs. Pairing new insulation with air duct sealing and a smart thermostat can amplify your savings even further.

For most residential attic insulation projects, installation takes between 2 and 6 hours depending on the size of the space and the depth of insulation being installed. Crawl space and wall insulation projects may take longer. FairPrice technicians work efficiently and take care to protect your home — covering work areas with plastic sheeting and cleaning up thoroughly before they leave. In most cases, your home will be fully accessible and comfortable the same day.

Absolutely. FairPrice Heating & Cooling serves homeowners throughout the entire San Francisco Bay Area, including San Jose, Sunnyvale, Mountain View, Cupertino, Palo Alto, Milpitas, Campbell, Los Gatos, Fremont, Oakland, Hayward, San Mateo, Redwood City, and many more communities. Visit our service area page for a full list of cities we serve. No matter where you are in the Bay Area, our team is ready to help you improve your home's insulation and energy efficiency.