We often get asked if it is a good idea to replace old windows with new and better performing windows to save money. Usually to the surprise and relief of homeowners we most often tell them to stick with the ones they’ve got. Not to say that the idea of replacing windows is always ‘green washing’, but it’s not necessarily going to save energy and money once you run all the numbers, so we recommend that windows should only be replaced when renovating a home when they are in an “unsalvageable” state of disrepair or wood decay & rot.
Yes, old windows will leak more air and lose more heat than new ones, but there is an energy variable to consider with replacement of windows as well. Purchasing a new window will also have its own energy and carbon footprint in terms of raw material extraction, manufacturing and transportation.
As warm air touches windows it cools and drops. This creates an air convection within a home, this sensation is most noticeable on very cold days, but can be significantly reduced with high quality triple pane windows.
The cost of replacing windows is pretty high and predominantly labour based; partly in manufacturing, but you have to factor in the cost of installation and finishing as well. So if you’re going to replace old leaky windows, you might as well get good ones. To go to all that effort and install a low-quality double-pane window doesn’t make sense from a financial point of view, or even quality of life. If you want to learn why we get condensation on windows and how to stop it, see here.
Upgrading a potential purchase from double to triple pane usually means an additional 20-25% on the sticker price, and there is a relatively quick payback on that added investment that comes from energy savings if in the end you are going to buy some. Beyond energy savings, a triple pane window offers greater durability, reduced sound transmission and a noticeably more comfortable home on cold days. All that is to say, you need to know how to choose the best windows for your house here and see here to know which type of window frame to choose between wood, aluminum or PVC / Vinyl
Will replacing old windows save money?
The short answer is, it’s not likely. From a standpoint of saving money, a complete home window replacement job rarely justifies the cost, although it depends if extensive work is going to be needed to renovate old windows too. For full disclosure before we do ‘our’ math, we don’t like vinyl and we would only ever install triple pane windows with Low- E coatings and wood or fiberglass frames – or the new generation suspended-film insulating-glass windows or glazing units..
A truly accurate assessent of whether or not you should replace windows would take a quote of the windows you want and possibly energy modeling of your existing winodws and potential new ones to see how far out your payback period would be be, but to quickly do your own very rough guesstimation – imagine the cost of a good quality triple pane window of perhaps 4×5 feet; call that about £1,200 for arguments sake. Now add installation and finishing costs – we’ll conservatively call that £400 to install, insulate, and replace trim inside and out.
Now look at your heating bill and figure if it is even possible to recoup the replacement cost of a window through added energy savings from that individual window. How long will it take to save £1,600 worth of heat through a better window, and will you even live that long? In most cases it is unlikely that you will be around to see a return on your investment. The window itself most likely won’t last as long as it takes to recoup the money before needing to be replaced again.