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Choosing the most appropriate window for its purpose and location involves understanding each of its components. Frame materials, glazing options, window performance metrics and labels are crucial components of window specifications. It is important to consider cost, aesthetics, durability, energy performance, and lifecycle environmental impacts of each component before choosing the best option for your project.


Selecting a frame material


Here are some key takeaways for choosing the most appropriate window frame material:


Vinyl is the current market leader due to low cost and low maintenance.1 However, vinyl is not easily recyclable and releases harmful chemicals and fumes during production.5 Check out this post to learn more about the dangers of PVC.

Aluminum is reported to have poor energy efficiency and energy-intensive production by the USGBC. However, aluminum is recyclable.

Wood is natural and renewable. Wood is most energy-efficient when not expanded, rotted, and warped.9 Reapplying paint or stain over time keeps it long-lasting.1

Fiberglass is known for durability and strength. It is used in the highest-performing windows and doesn’t release harmful chemicals into the environment during manufacturing. However, this material is not easy to recycle and can be expensive.1

Composites and other frame materials mentioned above can be combined to take advantage of each of their strengths.1


Consider glazing options


Glazing options play a large role in energy performance and environmental impact. These options include the number of panes, type of infill gas, kind of coating, and glazing spacers.1


Panes – Double and triple pane glazing are becoming standard. Each pane is separated by a spacer and creates an insulating air pocket to prevent heat transfer. A spacer carries a dessicant, a moisture-absorbing medium, to prevent moisture that harbors mold and mildew.6

Infill – The use of low-conductivity gas infill, such as krypton, performs better in reducing conductivity of heat than argon, a more popular option.1 Low-conductivity gas is infilled in the air pocket to prevent heat transfer.7

Coating – Low-e, or low-emissivity, coatings applied to the glass allow for short-wavelength sunlight to pass through while blocking long-wavelength heat radiation. Blocking heat radiation allows for more energy efficiency inside.1 Low-e coatings are non-toxic.4 The most common type is soft or sputtered coat.6 Single, double, and triple coatings exist. 

Spacers – Warm-edge glazing spacers help to seal the perimeter of the insulated glass unit (IGU). They also maintain the distance between the panes of glass to create the air pocket filled with insulating gas.8


✓ When choosing frames, here are our material recommendations in order of least detrimental to our health and environment:


  • Fiberglass frames or wooden frames
  • Aluminum frames
  • Vinyl frames

✓ Be sure to:


  • Choose double and triple pane glazing.
  • Use dessicant to hinder mold and mildew growth in spacers.
  • Prefer low-conductivity infill like krypton for heat transfer prevention.
  • Use low-e coatings for energy efficiency.
  • Specify climate specific solutions.