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Types of window frames and glazing that help to build energy efficient windows

Silvia Watson Silvia Watson
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Several features and technologies work together to make windows energy efficient and improve its durability, functionality, and aesthetics. You must understand how the features blend to produce the best quality windows so that you can select the right type of window for your home

Frame choices

The window frame contributes immensely to energy efficiency, and you must pay attention to the material used for the frame. Every window frame material has a designated U-factor which indicates how fast it transfers heat and the most common materials are wood, aluminum, vinyl, and fiberglass as well as a composite material.

  • Aluminum frames

Aluminum is a light and robust metal that requires almost no maintenance and is weather resistant too, which makes it durable and suitable for window frames. But it is never good for energy efficient windows because it transfers heat rapidly and has poor insulating properties. To make the window energy efficient, you must have a thermal break by inserting a plastic strip between the inside and outside of the frame and sash. 

  •  Wood frames

Wood has better insulating properties than aluminum but requires higher maintenance. Cladding wooden frames with vinyl or aluminum might lower its thermal performance slightly.

  • Vinyl frames

Vinyl windows use PVC, or Polyvinyl chloride impregnated with UV stabilizers to enhance its UV resistant properties that prevent the material from breaking down due to sunlight. Vinyl frames are maintenance free and do not require painting besides being moisture resistant. It can last for years with periodical washing with soap water for cleaning. To improve the insulation quality of vinyl frames, it is possible to fill the cavity of the frame with some insulation material.

  • Fiberglass frames

These frames are similar to vinyl frames and a new addition that have stable dimensions and to improve the insulation, you must fill the cavities of the frame with some insulation material. It can be a good replacement for wood or non- insulated vinyl.

  •  Composite materials

A combination of particle board and laminated strand lumber is a type of composite window frame material while some variety might use polymer plastics as the blending material. The composite materials are very stable and possess the same or better thermal and structural real estate properties of wood and have superior moisture and decay resistant property.

Glazing or glass

The choice of glass contributes to the energy efficiency of windows in your architecture, and there are a few options to choose from. Providing some coatings on glass improves its thermal efficiency and insulation.

Insulated windows

The standard insulated window consists of two or more glass panes sealed hermetically by maintaining some space between the panes as an air gap. These windows have low U-factor and low SHGC.


Glass with low e-coating improves the control of heat transfer rate and improves window energy efficiency. The coating consists of an invisible layer of metallic oxide applied to one surface of the panes.

The right combination of frame and glass should help to achieve the desired level of energy efficiency.