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Well over 50 percent of windows purchased today are vinyl windows. Choosing a superior vinyl window can be difficult if you don’t know what to look for.

It can prove even more frustrating if you buy your vinyl windows and have them installed only to find that they’re poor quality, uneven and already fading in appearance.  

Even worse, what’s very, very common is they look and operate ok for 3-5 years – then they quickly begin to lose their operating ability and looks.  Trying to collect on the “warranties” on these cheap windows, with bad installation, is a huge uphill battle, usually lost by the homeowner. 

There’s more to choosing and installing vinyl windows than meets the eye. 

What to Look for in a Vinyl Window

How a window is made and installed is more important than the looks, or how nice the salesperson was, since the internal structure determines a window’s integrity and longevity.

In this article, we’re going to focus on the window itself.  I’ll save the discussion on installation for a later blog.

As a homeowner shopping for the best vinyl window, consider these factors:

Vinyl: Look at a cutaway view of the window (sometimes called a corner cut) to identify the quality of the vinyl and the thickness of the window’s components. A thicker vinyl ensures rigidity and more overall resistance to weather damage.  This is exactly where most windows flunk.

Jambs: The vertical members of the window frame, thicker jambs provide better overall performance of the operating parts of the window called the “sash.” Building-grade windows have jambs from 2-7/16 to 3 inches thick, while premium grade windows offer 3-1/4 inch jambs.

Joints: Fusion-welded frames and sash: Maintaining a window’s square form helps ensure proper installation, in addition to creating a sharp look. Fusion-welded frames and sash can make a big difference here; windows that utilize a four-point welding system for the head, sill and two side jambs, and for the sash are sturdier and less likely to crack or break.

Chambers: These internal cavities within the frames and sash trap air, which insulates against heat and cold transfer through the window. Thick, multi-chambered frames and sash greatly improve structural performance by reducing the amount of seasonal expansion and contraction.  Building-grade vinyl windows generally have two to three internal chambers whereas premium grades have five, six or seven chambers offering superior energy efficiency. 

Beware of the window companies that use spray foam in the cavities, saying that it’s much better insulation value.  Hogwash. The insulation value of the window frame doesn’t really change. The payback on this supposed upgrade is decades, if at all.

Sloped sill: It’s not the thickness that matters here; instead, consider the degree of the slope of the window’s sill. Pockets seen on some vinyl brands will not keep water from collecting inside and outside of the window. A higher slope will allow for rainwater to hit the sash and flow downward, away from the window. This prevents water spots on the glass, and wear and tear on the vinyl.

Spacers: The material used to join two pieces of glass together to form a dual-pane (or insulated) window — a spacer’s material composition will affect air transfer. Aluminum spacers provide either a stuffy or chilly atmosphere depending on the season. Stainless steel and alloy spacers minimize the transfer of heat or cold through the window and minimize condensation on the windows, which is often caused by higher humidity levels in a home.

Glass: High performance glass, is something to look for.  Vinyl windows, in general, are more energy efficient than wood windows. High performance glass gives homeowners even greater latitude to keep energy costs down. It also provides some of the best protection you can find against fading of home interiors caused by the sun’s rays.

How do you find the replacement window information?

Inspecting the labels on vinyl windows is an easy way to check and compare the quality. One good label to check is the NFRC (National Fenestration Ratings Council) label. The NFRC is a non-profit organization which provides highly accurate measurements and comparisons of a window’s energy performance. An NFRC label will contain 4 different categories.

The first of these is called the U-value. This measures how well a window keeps heat from getting out. Lower U-values are always more desirable than high ones.

The next reading to check is called the Solar Heat Gain Coefficient (SHGC). The SHGC shows a rating between 0 and 1, and it tells how good a window is at blocking solar rays. (Lower numbers are also better.)

The VT or Visible Light Transmittance rating measures how much light penetrates a window or door. The higher the VT, the more light can come through.

The last rating that you should notice is Condensation Resistance (CR): this rating measures how well a window can resist condensation on the inside of the window. The higher the number, the better.

You can do it!

Making sure you get the best replacement windows for your money is often as easy as reading some common labels and knowing what to look for in regards to the build quality of the window.  A lot of shady companies try to skimp.  Though there are also some really good windows available.  If you are unsure, take a few pictures and send them to us to get our opinion.

Jim Edwards is the Home Advocate.  His clients love how he tells you right where to look to get the best information about home improvements.  He has seen it all, fixed it all and helped homeowners get the comfortable home they dream of.