That's no coincidence. Our fiberglass windows and replacement fiberglass windows are designed to match the beauty and profile of solid wood windows, while providing the strength, durability and performance of fiberglass windows. Milgard's own fiberglass production process enables us to make the complex profiles required for the look of painted wood windows on the exterior, with the option of choosing fiberglass or natural wood for the interior. Our process also allows us to engineer superior fiberglass windows that are impervious to water, cold, heat, insects, salt air and ultraviolet rays. Add to that our Full Lifetime Warranty with Glass Breakage and you have energy-efficient fiberglass windows that maintain their beauty.