Pella® Impervia® Fiberglass Casement Window
$$-$$$
When it comes to performance, Pella Impervia fiberglass casement windows are an overachiever. Made from our incredibly strong, proprietary fiberglass material, casement windows are hinged on one side and vent open on the other. A revolutionary Easy-Slide Operator hardware allows you to open and close your windows with one simple motion. And with a durable powder-coat finish, Pella Impervia casement windows deliver a timeless, long-lasting look.
Impervia Casement Window Features
Why Fiberglass?
- Superior strength with our proprietary fiberglass material61
- Rot- and corrosion-free
- Tested for the extremes and suitable for all climates
- Heavy-duty powder-coat finish, including Black
Enhancements
- Innovative Easy-Slide Operator hardware solution is available
- Solid- and dual-color frames in an up-to-date color palette
- Matching fixed and operable styles available for larger window combinations
- Durable three-way corner joints for added strength, durability and reliable water performance
Inside Pella Fiberglass
Pella Impervia windows are created from our exclusive fiberglass formula. A structural mat places rovings in a specific, intricate order to meet our high strength standards. Additional layers of strategically placed rovings are added, then the materials are pulled through a machine, injected with polymer resin and heated. It creates an entirely new, thermoset material which won't break down when exposed to the elements or lose its shape in extreme heat — unlike other materials.

For the Pros
Pella Impervia Casement Window Specs & Install Details
- Unmatched strength and lasting durability for proven performance and sleek style
- Tested and designed for the extremes
- Operable casement windows available in sizes up to 37-1/2” x 79-1/2”
- Fixed casement windows available in sizes up to 71-1/2” x 79-1/2”
- Performance class and grade LC40-LC50
Product Downloads
Options for Pella Impervia Casement Windows
Choosing Your Window
Combinations
Make a design statement with window combinations. Additional combinations are available. See your Pella sales representative for the complete offering.
For Pros
Combination Design Considerations
- Made just for your remodel or new construction project, unique and large factory-mulled assemblies help save time on the jobsite.
- Integral mullion, tight mullion, 1/2” structural mullion or 1” structural mullion with additional steel reinforcements.
- Residential and light commercial solutions designed and tested to ASTM E330 for structural test pressures up to 75PSF (DP50).
- Meet or exceed structural framing requirements of the International Building Code section 2403.3 for more demanding commercial casement and awning window applications.
- Ability to choose a solution based on project classification, including structural framing requirements for casement or awning specified projects.
Interior Finishes
Pella Impervia fiberglass products have a long-lasting factory powder-coat finish in your choice of five colors plus dual-color frame options. Learn more about interior finishes.

Black
For Pros
Materials
- Pella Impervia windows are made from our proprietary fiberglass material, the strongest material for windows, engineered for lasting durability.61
- With relentless strength and long-lasting durability, Pella’s proprietary fiberglass helps ensure less maintenance with fewer callbacks.
- Our long-lasting powder-coat finish meets AAMA 624 which is the highest rated fiberglass coating among leading national competitors.
- Exclusive thermoset material won't expand, warp or sag in summer heat, or shrink and turn brittle in harsh winter conditions.
Styling Your Window
Hardware
The Easy-Slide Operator is a revolutionary way to operate your casement and awning windows. Simply slide to open and close, without the effort of cranking. Or select the fold-away crank, that folds neatly away, against the window frame. Both solutions allow roomside window treatments to hang neatly in your room.

Black
Grille Patterns
Grilles give the appearance of individual window panes. Pella offers many grille patterns to help enhance your home's architectural style.

Prairie
Grille Profiles
Grilles-between-the-glass create the classic look of individual windowpanes. Learn more about grille profiles.

3/4" Grilles-Between-the-Glass
Window Enhancements
Screens
Flat Screens
Conventional fiberglass screens come standard.
Pella InView™ screens let in 14% more light and are 8% more open for improved airflow compared to conventional fiberglass screens.5