Why This Matters
Glass is a poor thermal barrier. Even double-pane windows transmit significant solar heat — especially on south- and west-facing exposures where the sun angle is most direct.
Near Exploratorium in San Francisco, west-facing windows at low afternoon sun angles drive the highest interior temperature increases. This is especially problematic for historic or older home installations, which older single-pane windows benefit most from low-e retrofit film to improve thermal efficiency.
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
Professional installation ensures the film is applied without bubbles, gaps, or edge lifting — all of which reduce effectiveness and shorten lifespan.
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 Exploratorium in Mission District, 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 historic or older 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