Best Fiberglass Windows
Explore our recommendations and opinions on the best fiberglass windows on the market. Certainly there are other options out there but these are four selections that we like and feel offer the consumer some good value for their money. Use our window cost estimator to find accurate pricing on fiberglass windows.
Alpen 925 Series
The Alpen 925 fiberglass window is the premium series that gets up to a 9.1 R-value through a quadruple pane glazing, a foam filled main frame, as well as a number of additional energy saving features. With the 9L glass package, the 925 casement achieves a 0.15 U-factor, .22 SHGC and .34 VT and gets some 99% UV blocking. The 925 window is available as a fixed frame, casement, awning, sliding patio door, half circle, several geometric shapes or as a bay or bow window.
Sunrise Restorations Series
The Sunrise Restorations window is more of a hybrid between a vinyl and fiberglass. The frame is vinyl, but it uses a fibercore reinforcement along the sash and meeting rail. A really high end window that combines the best of both worlds; a narrow frame, strength, great energy efficiency numbers, and a "reasonable" price tag.
The window includes a great tilt sash mechanism, and high transparency screen. Expect a U-value of 0.27 and air infiltration of 0.04, all in a very nice looking package. This window tops the list of both vinyl and fiberglass windows. It's a true double threat and a great all around window!
Marvin Infininty Series
The Marvin Infinity comes in either a full Ultrex fiberglass frame or an Ultrex clad model with an interior made of Everwood, a wood veneer that looks great but doesn't require the maintenance that real wood needs. A thicker frame and more bells and whistles explain most of the price difference between it and the Integrity. It also has a nicer finish and a better warranty, which covers 20 years for the glass and lifetime for everything else. It's really regarded as a top notch window.
Marvin Integrity Series
The Marvin Integrity is the company's low end fiberglass window. There are two varieties, either a full Ultrex or a wood interior with Ultrex cladding. They have fewer options when it comes to color, hardware, etc. Most insiders would recommend the Infinity, which has a lot more features and better ratings without being a lot more expensive. It comes with the Cardinal glass package, which has a 20 year warranty on the glass, lifetime frame coverage and 10 years for defects. The cost is reasonable for a good fiberglass clad wood window.
Milgard Ultra Series
The Ultra, Milgard's fiberglass window frame, is decent but often rated behind Marvin's Integrity and Infinity when looking at fiberglass. It doesn't have the curb appeal of some competitors, but it does have a great option for a real wood interior. The warranty is very good and it's a great choice if you really want fiberglass but can't quite afford the Marvins.
Inline produces quality fiberglass window and seem to really stand behind their work. Their windows are expensive and they offer a number of different styles that all have a different Series name (this is why we didn't recommend a particular series or model). They use good quality glass with high SHGC that helps optimize passive solar energy. The company has a base window and price that does not include any upgrades. All upgrades are priced out a la carte so the prices can really jump for a high end product. They are out of Toronto California and their distribution is more regional than the other fiberglass windows.