Selecting the best options for replacement windows depends on each individual circumstance and involves multiple considerations. The choice of glass is one of the options homeowners will need to consider.  The range of glass choices varies among products.  Normally, the number of options available increases as the price of the window increases. When a premium clad window is selected, choices usually include multiple low-e, tint and obscure glass options.  If the replacement window chosen includes glass options, the home’s specific setting should be taken into consideration when selecting glass. 

Visible transmittance (VT) measures the amount of natural light that the window allows to flow into the home.  Factors related to the home’s individual setting also impact the amount of natural light entering the home.  The window’s VT rating should be considered in combination with these other factors.  Careful consideration of the home’s setting along with the window’s VT rating will help ensure maximum enjoyment from replacement windows.

The following three factors have a substantial influence on the amount of natural light entering the home and should be considered when evaluating glass options:

  1. The amount of glass relative to the home’s size.
  2. Whether or not the home is in full sun, lightly shaded or heavily shaded.
  3. Whether or not window treatments will be layered over the windows.

Glass samples should be examined

Homeowners should always examine samples of the glass that they are considering.  To help develop perspective, these samples should be compared to samples that are both lighter and darker. It is important to examine a mock-up of what the actual window glass will look like, i.e. a double-paned insulated sealed sample.  One of the most effective ways to examine glass samples is to place each sample side by side on a white sheet of paper.

Natural light has a major impact on a home’s appeal and can also influence a home’s market value.  Taking time to understand VT and considering a window’s VT rating in combination with other factors that influence the amount of natural light entering the home is important. Replacement windows are a significant investment. Proper consideration of VT will help homeowners achieve the outcome that they are envisioning from their replacement window project.