We work with a lot of REALTORS who represent buyers and this is one of their most common questions. Many consumers believe that because vinyl windows tend to look similar, they are all equal in quality, but they are not. Two key ingredients to a quality window are the efficiency and the strength of the window. Just because a house has windows that go up and down, tilt out for easy cleaning and are double pane doesn’t mean the windows are efficient. Nor does it mean they are structurally strong and will continue to perform down the road.

There are a few things to consider when assessing the efficiency and strength of a window. First, take a look at the type of spacer system that is the window. The spacer is used to separate the 2 or 3 panes of glass in the window and is also used to seal in the Argon Gas, which is often present between the panes to make the window more efficient. A premium spacer system will limit thermal conduction, making your windows more efficient and your home more comfortable. A full metal spacer can act as a thermal conductor which means the edges of the glass will feel cold in the winter and warm in the summer. Full metal spacers can also promote condensation issues on the exterior panes of glass.  Metal should be used since it is stronger than foam but it should be a low conduction alloy.  This will also add to the overall strength of the unit.

Another thing to look for is the thickness of the vinyl extrusions that are used during the manufacturing process. Unfortunately, you can’t see inside the frame to determine the thickness, so instead, you should tilt the sash and feel its weight. If it feels light, it is most likely made with thin vinyl extrusions, which is an indication of a lesser quality window. Some window manufacturers reduce the cost of their windows by using fewer materials or by using inferior parts and pieces to construct their windows. The benefit of thicker vinyl extrusions is that the frame will better support the weight of the glass, which means less chance of seal failure and less chance of the window sagging in the future. A sagging window can make the window harder to operate and/or lead to air infiltration issues. The bottom line is that your windows should be efficient, easy to use, and built to last. So, feeling the weight of the sash when you tilt it, and looking at the spacer are the two main things I tell consumers to do when they’re looking at existing vinyl windows.

If you have any questions about windows or replacement windows, call us at (540) 259-5656.