Why This Matters
Solar heat gain through windows accounts for 25–30% of residential cooling load in California homes. That's the single largest controllable source of summer heat gain.
Near San Francisco State University in San Francisco, west-facing windows at low afternoon sun angles drive the highest interior temperature increases. This is especially problematic for single-family home installations, which the most common residential application; window film reduces heat gain and protects furnishings.
California's Title 24 energy code sets minimum window performance standards for new construction. Window film can bring older homes up to — and beyond — those standards at a fraction of the cost of window replacement.
The Solution
Film selection for south- and west-facing windows should prioritize solar heat rejection. For north-facing windows, UV protection and glare control are typically the primary goals.
Low-e retrofit film is specifically designed for older single-pane windows. It adds a low-emissivity layer that dramatically improves thermal performance — the most cost-effective upgrade for pre-1980 California homes.
Retrofits existing glass with a low-emissivity coating for improved thermal performance.
Climate & Solar Performance
Properties near San Francisco State University in St. Francis Square Cooperative, San Francisco experience afternoon heat gain conditions that make window film particularly effective. Low-E Retrofit Window Film is specifically engineered to address this solar exposure.
Effective against afternoon heat gain
Rated for single-family home protection
Professional installers available in San Francisco
10–15 year manufacturer warranty
Installation Guide
Some installers offer a complimentary solar assessment — they'll visit your property, map your sun exposure by orientation, and provide a written film recommendation before you commit to installation.
Install time
30–45 min
Per window
$150–$400
Cure time
30 days