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Our best value fiberglass windows525 Series

Alpen Windows 525 Series, powered by Alpenglass, are our best value fiberglass windows, delivering thermal and structural performance at an affordable price. These low maintenance windows require no sanding or painting and can be installed in new construction and remodeling/replacement applications. Alpen Windows 525 hand-crafted, custom made windows have an optional wood interior which delivers the beauty of wood on the inside with the durability of fiberglass on the outside.

Benefits of Alpen Windows 525 Series:


  • Thermal performance up to R-5.9
  • 99.5% UV protection
  • Our highest value fiberglass option
  • Virtually maintenance free
  • Reduced interior condensation
  • Unique design keeps the window warmer in the winter and cooler in the summer
  • Architectural freedom allowing for more glass in your design
  • Can contribute to LEED credits

Please Contact Us for Technical Information on the Alpen Windows 525 Series.