Why This Matters
The afternoon sun angle in Southern California between June and September is low enough to drive direct solar radiation deep into west-facing rooms. Standard window treatments block the view; film blocks the heat.
Near Sunrun 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
Residential window film is the most targeted solution for solar heat gain: it addresses the problem at the source — the glass — rather than compensating with more cooling.
Anti-reflective film is the most targeted solution for glare: it reduces peak window luminance without significantly cutting total light transmission. Best for rooms where screen visibility is the primary concern.
Retrofits existing glass with a low-emissivity coating for improved thermal performance.
Climate & Solar Performance
Properties near Sunrun 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 single-family home protection
Professional installers available in San Francisco
10–15 year manufacturer warranty
Installation Guide
The best time to schedule installation is in the morning, before the glass heats up. Hot glass causes the slip solution to evaporate too quickly, making it harder to position the film correctly.
Install time
30–45 min
Per window
$150–$400
Cure time
30 days