Windows provide more than just light — it’s time to dive into the processes, benefits, and options with various building materials.
Windows don’t simply emanate light into rooms anymore. Today they can affect everything from biophilic design to circadian rhythm to energy efficiency. Whether you’re a designer, contractor, or builder, there are many considerations to think about when choosing the best windows for a homeowner’s project. It’s important to have a solid understanding of the following topics when approaching a project.
- Performance classifications and grades
- Testing
- Manufacturing processes
- Performance benefits
- Design options of various window types
Each of these considerations align with the 2017 edition of the North American Fenestration Standard (NAFS), which currently defines the performance requirements for windows, doors, and skylights made of aluminum, vinyl, ABS plastics, fiberglass, cellulosic composites, and wood.
These vinyl windows not only let in plenty of light and scenery, but they’ll last for years with their strength and enduring performance.
1. Four performance classifications and grades
Performance classes help differentiate windows according to their suitability for a particular application. NAFS has four performance class categories: R, LC, CW, and AW. Manufacturers will determine whether or not the desired rating and test products meet all of NAFS performance requirements for that class based on a minimum gateway test size and other testing requirements.
- “R” is commonly used in one- and two-family dwellings, and the minimum performance grade is PG15.
- “LC” is frequently used in low- and mid-rise multifamily dwellings or buildings with larger sizes and higher design wind load requirements. The minimum performance grade for “LC” is PG25.
- “CW” is often used in low- and mid-rise buildings with larger sizes, loading, and limits on deflection — the minimum performance grade is PG30.
- “AW” is used in mid- to high-rise buildings with increased loading and limits on deflection. The minimum performance grade for “AW” is PG40.
Check out these tips from JELD-WEN in order to learn how to understand and calculate the performance grade for your project.
2. Testing
Builders need to pass several window performance tests that the NAFS requires before moving forward on a project. These performance requirements test air leakage, uniform design, uniform structural lads, water penetration resistance, forced entry resistance, hardware load testing, and operating force. The selected products need to provide the required performance for the project’s unique mix of climate conditions, height of installation, type of building, type of fenestration product, and durability.
Think about which material—vinyl, wood, or clad wood—will be best for your project regarding climate, air filtration, finish treatment, and performance over time.
3. Manufacturing processes: vinyl vs. wood
Today’s manufacturing processes result in windows with features and performance designed to meet or exceed code restrictions.
Vinyl: During vinyl windows manufacturing, stainless steel dyes produce extrusions, ensure smooth surfaces, and produce premise dimensions for assembly. Vinyl windows also comprise thick thermal walls to improve strength and energy performance. Tight seals reduce air infiltration and prevent water leakage.
Wood: For wooden windows, manufacturers often use water-based manufacturing processes to penetrate and fortify the material all the way to the core, providing a higher level of protection. Clients can preserve the beauty of a wood window investment with fortified pine—such as JELD-WEN’s Auralast Pine—that protects against any harsh climate, moisture, or termites.
4. Performance benefits: vinyl, wood, and clad wood
When comparing vinyl to wood to clad wood, it’s important to be aware of the benefits of each one to make the best decision for the project.
Vinyl: This material is known for durability, energy efficiency, and low maintenance while meeting aesthetic demands within budget. Vinyl also won’t chip or peel and is virtually maintenance free, as the finish stands up to scratches and heat degradation. Available in a wide range of features and options, vinyl is often used in coastal homes that endure harsh climates but has gained popularity in recent years in all regions.
Wood: While wood does provide exceptional insulation, it maintains its principal properties even throughout changes in temperature. Visually, wooden windows create a warm, inviting feeling to contemporary and historic spaces alike. Wood also allows for endless customization options, handling various treatments and finishes well.
Clad wood: Clad-wood products are similar to wood but offer improved performance and architecturally rich designs that can best accentuate historical, high commercial, and coastal buildings and homes. Manufacturers often add details for casement and double-hung windows, adding strength and reliable performance.
Windows with JELD-WEN’s AuraLast pine are protected from water, rot, and termites, especially for contemporary homes that need to withstand the test of time.
5. Design options for window products
Consider each of the various design options for windows, as each factor has a great impact on windows’ appearance, functionality, and performance.
Style: With design styles out there, there are certain styles that are best for specific projects. Awnings and casement windows help provide ventilation, and when built with AuraLast pine, provide protection against rot, water damage, and termites. Double-hung windows are ideal for historic renovations, mixed-use developments, or residential homes. Then, geometric and radius windows are well suited for lighting stairways and other dark areas of a home.
Finish: All windows with JELD-WEN paints and finishes are engineered to meet the American Architectural Manufacturers Association (AAMA) standards. There are a variety of differing finishes for interior and exterior projects that accentuate a home and make each window last for years. Interior finish options include stain, wood (pine, alder, or Douglas fir), paint, or anodized finishes. Exterior options include various paint colors and anodized finishes, both of which are required to meet the AAMA standards.
Frame: Windows are available with a variety of frames to make installation easier, providing a streamlined appearance. Brickmould and integral flat casing are ideal for new constructions that need a simple, secure installation. Pockets and flush fins both work well as replacement windows, covering an old window frame for a cleaner look without disturbing exterior siding, interior trim, paint, or wallpaper.
Energy performance: There are numerous options for glazing that can maximize energy performance, though they typically vary by each manufacturer. The most cost-effective, energy-efficient update is double-pane, which reduces heat loss up to 30%. Alternatively, triple-pane provides maximum protection, even in the harshest weather, reducing heat loss up to 50%.
For assistance with window specification or installation, visit JELD-WEN’s professional portal.
