While DIY saves money, professional installation ensures the warranty remains valid. Get at least from local contractors.

How much sun heat enters (lower is better for hot climates). Low-E Coating: A microscopic layer that reflects heat. 5. Hire a Pro vs. DIY

Check for licenses, insurance, and manufacturer certifications.

Your (for a single window or whole house). The climate you live in (extreme cold, coastal, or desert).

Look for the label and pay attention to these ratings: U-Factor: Measures heat loss (lower is better).