Now I Have Home Replacement Windows: What Do I Do With My Storm Windows? After having vinyl home replacement windows, fiberglass home replacement windows or wood home replacement windows installed, many homeowners find themselves asking: what in the world do I do with all of these storm windows? Storm windows a temporary, exterior window, designed to be fitted over existing windows during inclement weather were once a necessity. Most homeowners are familiar with the routine of installing storm windows every fall and pulling them all down again once warm weather arrives. They provided that extra layer of insulation needed to keep the cold out and the warm in. Yet storm windows cannot conserve energy as well as modern replacement windows. More than one home owner has pondered installing their storm windows over their new replacement windows, as a way to gild the lily. After all, if storm windows are good, and replacement windows are good, shouldnt replacement windows and storm windows together be good? The answer is not necessarily. There are a number of problems installing storm windows over new replacement windows. The first problem is the obvious issue of fit: your replacement windows may not be the same size, exactly, of the windows you replaced, which means your storms wont fit. Installing storm windows annually will now be a bigger chore than it was before. Storm windows are not designed to work with replacement windows. They trap heat and moisture between the panes of glass. This can result in fogging, obscuring your view and adding unwanted moisture. Additionally, the heat trapped by storm windows can actually damage your replacement windows, if youre in a very warm region. Meanwhile, youve doubled the number of surfaces you need to clean. While home replacement windows feature easy tilt-in cleaning, storm windows do not. Youll be back on the ladder with the soap and water or enjoying dirty, cloudy windows by the end of the winter! At the same time, one has to consider how much benefit one is realizing by installing storm windows over thermal replacement windows. The answer to that question is Not very much. Adding another layer of glass to a double-pane or triple-pane thermal window does add mass to the entire unit, but it does not markedly increase the insulating capabilities of the window. When one weighs the inconvenience, unsightly appearance (for many storm windows are far from attractive!), extra work, and difficulty maintaining storm windows against the minimal benefit gained by installing them, the choice becomes clear. Theres no reason to install storm windows over vinyl replacement windows, fiberglass replacement windows, or wood replacement windows. Still, its a shame to see all of the still-perfectly good storm windows you have go to waste. Consider donating these windows to Habitat for Humanity or other local housing-oriented charity. They can certainly use the materials, particularly to upgrade homes that dont have storm windows and dont have the budget available for home window replacement. Youll be doing real good in your community and youll enjoy a charitable tax deduction.