Why This Matters
Low-e coatings on double-pane windows are optimized for winter heat retention. In summer, they still allow significant solar heat gain. Window film corrects this seasonal imbalance.
Near HCI Solar in Berkeley, 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.
The California climate — 260+ sunny days per year in most regions — means solar heat gain is a persistent challenge. Window film addresses it at the source, without blocking your view.
The Solution
Low-e retrofit film is the most cost-effective upgrade for older single-pane windows. It adds a low-emissivity layer that dramatically improves thermal performance without full window replacement.
Perforated film solves the privacy-versus-light tradeoff for street-facing rooms. The micro-hole pattern maintains outward visibility from inside while blocking the view from outside during daylight hours.
Retrofits existing glass with a low-emissivity coating for improved thermal performance.
Climate & Solar Performance
Properties near HCI Solar in Solar Car Wash, Berkeley 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 Berkeley
10–15 year manufacturer warranty
Installation Guide
Film curing takes 30 days after installation. During this period, you may notice small water bubbles or a hazy appearance — this is normal and will resolve completely as the adhesive cures.
Install time
30–45 min
Per window
$150–$400
Cure time
30 days