Window Certifications

Our replacement windows are certified by the Energy Star program.

Vytex replacement windows, sold by Keystone Window of Pennsylvania, are backed by several nationally recognized organizations responsible for maintaining industry ratings and standards. 

Our windows are among the most energy-efficient available, installed by our own factory-direct certified crew, and backed by a Transferable Lifetime Warranty. You won’t find a better value anywhere else.

Our Vytex replacement windows, sold through Keystone Window of Pennsylvania, are certified and trusted by top-rated national organizations:

NFRC Certified (National Fenestration Rating Council) 

Keystone’s windows are certified by the NFRC, a trusted nonprofit that sets the standard for energy performance in windows and doors. This ensures every product meets strict thermal efficiency guidelines.

• Third-party, non-profit organization
• Administers the only uniform rating system for windows, doors, and skylights
• Provides credible data on energy efficiency and thermal performance
• The NFRC label reflects the tested performance of the full window unit
• Certification is required to qualify for ENERGY STAR®

AAMA Gold Label (American Architectural Manufacturers Association) 

Our Vytex windows meet the rigorous testing standards of the AAMA Gold Label program. This includes:

• Structural performance under high winds
• Air leakage resistance
• Water penetration resistance
• Uniform quality and manufacturing integrity

Gold Label certification means you can trust that our windows aren’t just stylish, they’re engineered for strength and longevity.

Energy Star Certified 

Keystone’s vinyl windows are Energy Star certified, making them an ideal choice for energy efficiency and comfort. All models meet strict criteria for:

• U‑Factor: To qualify for Energy Star, a window must have a U-Factor rating of 0.30 or lower.
• SHGC (Solar Heat Gain Coefficient): Blocking unwanted solar heat
• Regional Compliance: Tailored to Southeastern Pennsylvania’s four-season climate

Energy Star windows not only reduce your utility bills, but they also contribute to a smaller carbon footprint, too.

EPA Lead Safety Certification 

At Keystone Window of Pennsylvania, your family’s health and safety are our top priority. That’s why we go beyond standard installation practices to meet and exceed all EPA Lead-Safe Certification requirements when working in homes built before 1978.

Many homes in areas like King of Prussia, Doylestown, West Chester, and Malvern still contain lead-based paint. When disturbed during remodeling or window replacement, lead dust and particles can pose serious health risks, especially to young children and pregnant women.

We are committed to ensuring every member of our installation team is fully EPA-certified and trained in federally mandated lead-safe practices to prevent lead exposure. Our crews follow all safety protocols, including:

• Carefully containing the work area to prevent lead dust from spreading
• Using specialized tools and methods to minimize dust and debris
• Thoroughly cleaning the site during and after installation
• Properly disposing of all old materials in accordance with EPA standards

These practices may add to installation time and material costs, but Keystone Window does not profit from the extra steps. We invest in your safety because we believe protecting your home’s environment is non-negotiable.

Reminder for homeowners: Hiring an uncertified contractor for homes built before 1978 is not only illegal, it puts your family at serious risk. Choose a certified expert like Keystone to ensure compliance and peace of mind.