In the world of window shopping, understanding terminology is key. One of the most important questions to answer is what kind of installation are you interested in? There are two types of installation techniques, new construction and retrofit or replacement. Each technique is performed at different points in time and uses different tools. Lets dive into the differences.


New Construction

If you are building a new home, chances are you have hired a contractor. That contractor will build the house from the ground up. A new construction window comes with a “nail-on” flange. This is a piece that extends about an inch off the window and goes around the perimeter. This flange has spaced out holes in it so that after the framer is done framing the window, you can screw in the window to the frame. This is where a new construction window differs from a retrofit.


Now, if you are remodeling and adding windows in places that never used to have windows, you also use new construction techniques. So, you use a new construction window frame in the case that a window never existed in the place you are installing a new window.



If you currently have old, single pane windows installed in your home and you would like to replace them, this is the installation technique for you. A retrofit or replacement window comes either with a replacement flange or as a block frame. The windows are custom made to fit in place, or over your existing window. Now, the retrofit category is then broken down by the type of material your current windows are made from.



Old double hung wood windows are seen in older homes. They are very difficult to maintain and they require lots of maintenance. If you are interested in replacing your old wood windows, it's a good choice. Now, the way you replace old wood windows is you remove the inside stop, take out the old wood sashes, and install your “block” frame replacement window. What is a block frame? It is a new window which does not have any flange surrounding the perimeter of the window. So, if you look at the profile of the window, there is nothing that sticks out.



Old aluminum windows are most often replaced with vinyl windows. In this case, you order custom made vinyl windows to fit right over your existing windows. With this installation technique, the frame of your aluminum window stays in tact. You new window has a replacement or z-bar flange on the outside perimeter of the new window. This flange is there to cover the old aluminum frame so you will not see the old frame. The reason why you keep the old frame in tact is because, unless your window is leaking, you don't want to disturb the water membrane that was initially made when the house was built. The new window fits right inside the old window and you seal the window along the outside perimeter with caulking and foam in the inside. Cover with inside trim and you are all set.


There you have it. Now, time to think about what brand, material, and options you want in your new windows. Check out some of our other articles for more useful tips and information.