Heat flowing in and out through windows accounts for 25% to 30% of a home’s heating and cooling energy use. Window drafts are also a common problem that can lead to high energy bills and unstable indoor temperatures. Both factors can cause your home’s HVAC system to run longer to maintain a comfortable temperature, leading to increased energy costs.
Switching to energy-efficient windows can address these costly issues if done correctly.
This guide details the factors that make windows energy efficient and what to look out for when buying the right windows for your home, climate, and budget.
What makes windows energy efficient?
There are many factors that make windows more energy efficient, but glass type, coatings, gas fill, and frame material are priorities when purchasing new windows. You should also consider where you live and the orientation of your home, as certain features are better suited to different climates and sunlight.
The most energy-efficient windows have multiple panes filled with an inert gas (usually argon or krypton) that further insulates the window. Depending on your climate and maintenance preferences, wood, fiberglass, and composite frame materials are usually the most energy efficient.
Next, let’s think about painting. Windows with low-E coatings or films cost more, but can potentially reduce energy losses by 30% to 50%. A variety of low-e coatings are designed for hot or cold climates and can also control the amount of visible light that comes through your windows.
An often overlooked aspect of energy efficiency is installation.
“You can buy the best quality windows on the market, but poor installation can negate the energy efficiency benefits,” says Kirill Ratia, founder of Ratia Construction.
Latia said if a window installer or carpenter uses the wrong size nail, it can puncture a window’s sealing mechanism. A good installer will also need to place insulation around the windows, add drainage tape, weatherstripping around the sash, and finish the seal with caulk. Anything that compromises the airtightness of windows and their openings creates drafts.
About energy ratings and labels
Window energy ratings and labels can help guide buyers in making the best choice, but they can be overwhelming at first. Here’s a quick look at common energy ratings and labels and what you need to look for.
Window U-factor ratings provide insight into the energy efficiency of windows and doors by measuring heat transfer through the glass or pane. The lower the number, the better, as it indicates a more energy efficient product.
Solar heat gain coefficient (SHGC) is the amount of solar radiation that is transmitted or absorbed through a window, glass door, or skylight. The lower the SHGC rating, the better the product’s light blocking properties and the less solar heat transfer. Windows with a high SHGC rating will keep your home warm throughout the winter. Choose the SHGC-rated windows that best suit your climate and home orientation.
Visible Transmittance (VT) is a performance rating that measures the percentage of visible sunlight that enters your home through your windows. This rating ranges from 0 to 1, with 0 indicating no visible light enters your home. Generally, a higher VT rating is ideal because it reduces the amount of lighting needed in your home during the day.
Air leakage ratings measure how much air enters your home through closed windows. Look for windows with a low air leakage rating, which indicates they are energy efficient.
Finally, look for windows that are ENERGY STAR certified. This rating is administered by the U.S. Environmental Protection Agency and indicates that a product is energy efficient. For best results, match your window type to your home’s climate zone using the ENERGY STAR Climate Zone Finder.
How energy-efficient windows reduce energy costs
Energy-efficient replacement windows can help reduce the amount of heat lost from your home in the winter and keep you cool in the summer. If you live in a cold climate, gas-filled, low-emissivity windows can help reduce heat loss. In contrast, homeowners in warmer climates should prioritize installing solar control films or coatings on their windows to keep their homes cool.
With ENERGY STAR certified windows, homeowners can save up to 13% on utility bills when replacing single pane glass. If your electricity bill is about $150 per month, you’ll save about $234 per year. If your home has inefficient or outdated double-glazed windows, replacing them with more energy-efficient windows can reduce your energy costs and improve your curb appeal and resale value. However, these benefits often have long-term consequences rather than immediate savings.
When does energy efficient window replacement make sense?
Old or drafty windows account for 25% to 30% of your home’s heat coming in and going out, and can have a big impact on your monthly energy bills. If you notice increased energy costs, drafts, or condensation between window panes, consider updating your existing windows with caulking or weatherstripping, or replacing them entirely for best results.
Ideally, you’ll either replace all your windows at once (especially if they’re the same age) or work room by room to target the most egregious offenders.
Costs and considerations
The cost of windows varies widely depending on the window material, installation team, and energy efficiency features. Most homeowners can expect to pay in the following periods: $400 and $1,500 Per window (higher end of range reflects premium wood, fiberglass, or composite windows).
When purchasing windows, consider your local climate and which features are best suited to maintain a comfortable temperature year-round. By doing so, you can reduce your utility costs.
In terms of return on investment, homeowners can expect long-term results in several ways.
“Homeowners can typically expect to recoup 60% to 70% of their window treatment investment through resale, but the real payback starts right away with reduced utility bills,” says Phil Adkins, president of home improvement contractor Adkins & Sons. In my experience, most households notice a significant reduction in their energy bills within the first year, especially in areas with harsh winters and hot summers, where HVAC systems are working overtime. ”
conclusion
Choosing energy-efficient windows that are worth your investment depends on where you live, the orientation of your home, and your budget.
Prioritize energy-efficient features that suit your climate and choose products certified by reputable programs like ENERGY STAR to reap the most benefits. Before replacing, assess your home’s windows for drafts or lackluster features like single-pane glass to determine your needs. Then, work with multiple installers to collect multiple quotes and compare prices, warranty coverage, and personalized recommendations.
FAQ
What is a good U-factor for Windows?
A good U-factor for Windows is as low as is acceptable, typically around 0.20. A lower U-factor means your windows are better insulated, which helps reduce energy costs and keep your home more comfortable.
Are ENERGY STAR windows worth the cost?
Yes, ENERGY STAR windows can reduce your home’s energy bills by an average of 13% when replacing single pane glass. This makes it worthwhile for many homeowners, as it can save them hundreds of dollars a year in utility costs when upgrading from single-pane windows.
Is it better to replace all windows at once or one room at a time?
If your budget allows, we recommend replacing all your windows at once. This is because contractors can often offer lower installation prices and save on labor costs. Additionally, replacing all the windows in your home will make your home more energy efficient and help you save money on your energy bills.
