Getting new windows is one of the most satisfying ways to improve the efficiency of your home. You save energy and your whole house looks nicer from the street as well as from the inside.
But unless you really have old single-pane windows, replacing windows probably isn’t the most effective change you can make. Read on to find out if you really need new windows or if you could save more energy elsewhere in your house.
Return on investment
In most households, windows account for around 10% of energy loss. This is significant, but so is the cost of new windows.
An energy efficient window can cost anywhere from $ 270 to $ 800 to install, and you won’t see a difference on your utility bills if you don’t replace all of the windows. Homeowners who install Energy Star windows save an average of 12% on their running costs all year round. Updating old Energy Star windows with better new ones doesn’t provide the same savings as updating to new windows.
Windows is not the main source of energy loss. In fact, they’re not even in the top 5. If energy efficiency is your primary goal, you should take other steps first. Insulation isn’t as exciting as new windows and can cost just as much. However, by insulating your floors, walls and ceilings, you can save three times as much energy. By sealing ducts, you can save half the time you need to install windows, and at a fraction of the cost.
Sealing ducts can save half the price again than replacing windows at a fraction of the cost. Image source: Union of Concerned Scientists
However, these are averages, and there are other things to consider that can influence your decision.
You may already have good insulation, a stray baseball may have required a window replacement, or your windows may be exceptionally old. Some signs that it’s time to replace your windows are drafts, condensation on the panes, and mold or rot on the frames. For added security, you can use a home energy audit to determine if window replacement should be prioritized.
If you are a tenant, weathering your existing windows may be your only option. For homeowners with double glazing who are not performing, especially if they are still under warranty, repairs may be the more sustainable choice. Replacing these resources may be more resource efficient than the difference in energy efficiency. Rotten rocker panels and jammed wings can often be repaired. Weatherstripping and resealing can remove most drafts.
If you have an older home with original windows, you may want to keep them for architectural reasons and preserve the historic value of the home. You can make existing windows more energy efficient with a few DIY hacks. Window attachments such as year-round storm windows, insulated curtains, exterior shading and window foils can be used to influence seasonal heat loss and heat gain.
Buy the right Windows
Once you have decided on new windows, there are several factors to consider. Energy Star rated windows don’t all work the same. Consider the construction and materials of the windows. Although thermal break can improve them, inexpensive aluminum frames do not insulate well. Fiberglass frames generally perform better. Triple-glazed windows provide maximum efficiency, but the added efficiency may not outweigh the cost premium. Low-E glass coatings that reflect infrared light can minimize heat transfer.
Image source: Energystar.gov
The right windows for your home depend on your Energy Star climate zone and can be different for different sides of your home. For example, in cold climates, south-facing windows should have a higher solar thermal gain coefficient (SHGC) and a low U-factor to reduce heat loss. Windows facing east and west should have a low SHGC. In warmer climates where heat gain is a bigger concern, you’ll need a low SHGC for south, east, and west facing windows.
Window installation is a home project that requires professional help. Many window guarantees require professional installation. And if your home was built before 1978, there’s a good chance your window sills have been contaminated with lead paint, which is best removed by a certified lead reduction professional.
What to do with old Windows
While recycling old windows isn’t always easy, you shouldn’t undercut the benefits of your new windows by throwing out the old ones.
Building materials reuse stores often accept windows, or you may be able to use your old windows in DIY projects like building a cooling frame for the garden. You may even be able to turn them into solar panels. As a last resort, find a construction and demolition waste (C&D) recycling company to accept your windows.