Energy efficiency is a popular term today, but its true meaning and impact on your window purchase might not be immediately clear. This guide aims to provide all the essential information about energy-efficient windows before you invest in them for your home.
How Do Standard Windows and Energy-Efficient Windows Differ?
The fundamental design and functionality of an energy-efficient window distinguish it from a standard one. The materials employed in their construction vary significantly.
Here are some advanced characteristics of energy-efficient windows:
- Multi-Paned Construction for enhanced insulation, impact protection, and noise reduction.1 Energy-efficient windows are typically manufactured with two, and sometimes even three, panes of glass.2
- Special Coatings that reflect infrared light to retain heat indoors during winter and keep it out during summer.3 These coatings can also block ultraviolet light, which helps prevent furniture in your home from fading.4
- Insulating Fills between multiple panes of glass, using air or inert gas, provide superior insulation compared to a single pane.5
- Constructed with low-maintenance framing materials, such as fiberglass, vinyl, or composite, to reduce heat transfer and improve insulation.6
How Do Windows Achieve Their Energy-Efficient Standard Rating?
Energy-efficient windows are assessed and labeled by the National Fenestration Rating Council (NFRC), an independent non-profit organization.7 While the ENERGY STAR label indicates overall energy efficiency, the NFRC label offers a more detailed breakdown of a product’s energy performance, allowing for direct product comparisons.8 NFRC ratings provide insights into a window’s performance across the following categories:
- U-Factor: This metric quantifies how effectively the window insulates by measuring the rate of heat transfer.9 Windows with a lower U-factor are better insulators, so a low number is desirable.10
- Solar Heat Gain Coefficient (SHGC): This signifies how well the product blocks heat from sunlight by measuring the amount of solar energy transmitted.11 A lower SHGC indicates less solar heat is transmitted by the window, so a low number is preferred.12
- Air Leakage (AL): This gauges the rate at which air flows through the window’s joints. A lower AL value denotes less air leakage, making a low number favorable.13
- Visible Light Transmittance (VT): This determines the amount of visible light the window allows through. A lower VT means less light is visible, so if you prefer abundant natural sunlight, look for a high number.
Additionally, because windows are designed with various features, some perform better in certain climates than others.14 It is crucial to select the window type that is most appropriate for your specific climate. The United States is divided into four distinct zones: Northern, North-Central, South-Central, and Southern. Within each of these zones, performance criteria for windows and skylights vary, based on ratings certified by the NFRC.
What Are the Benefits of Energy-Efficient Windows?
Installing energy-efficient windows in your home offers numerous advantages.15 Here are a few key benefits:
Save Money
ENERGY STAR has estimated that an American home can save anywhere from $126 to $465 annually on heating and cooling costs by replacing single-paned windows. F16or double-paned windows, estimated savings range from $27 to $111 per year.17
Investing in new energy-efficient windows can lead to long-term financial savings by reducing your energy expenses.18 It’s estimated that 70% of energy loss in a home occurs through windows and doors, with a striking 90% of that loss happening through the glass itself. Avoid overworking your HVAC system; maintain warmth in winter and cool air in summer with energy-efficient windows.19
Increase Your Property Value
Beyond enhancing energy efficiency, upgrading to energy-efficient windows can potentially increase your home’s value.20 Updated windows not only improve curb appeal but could also encourage potential buyers to pay more for a home that won’t require new windows in the near future. Buyers also appreciate knowing their energy bills won’t be unusually high due to old, drafty windows.
Live Comfortably
Installing energy-efficient windows will help eliminate drafty or overheated spaces, ensuring a consistent temperature throughout your home.21 Old windows often have cracks in their seals or frames, allowing cold air to seep in during winter and hot air to creep in during warmer months, leading to uncomfortable drafts.22 This can also cause your thermostat to inaccurately register a low house temperature, leading to excessive heating in areas that don’t need it, resulting in overheated spaces. Energy-efficient windows can also help extend the lifespan of your window treatments, furniture, and floor coverings by reducing fading.23 Specialized coatings on energy-efficient windows can block UV rays 90% more effectively than ordinary glass.24
Guide to Energy-Efficient Windows
We understand that purchasing energy-efficient replacement windows can feel like a daunting task. This guide is designed to help you understand what to look for in quality energy-efficient windows and provide helpful tips and advice to assist you in the decision-making process.
Once you have a clear understanding of the buying process and the right questions to ask, you’ll be prepared to explore your window options. Consider these important tips before making a purchase:
- Research and compare window companies and brands — Ensure you are partnering with a well-established, reliable, and reputable window company.
- Decide what style of windows are best for your home — Most window companies offer a diverse range of window styles to meet individual needs and complement your home’s unique aesthetic, including double-hung, bow, bay, sliding, awning, casement, and custom-shaped windows.25
- Consider the quality of your replacement windows — Your energy-efficient replacement windows should be custom-made to fit your openings precisely, without the use of expansion pieces or fillers.26
- Understand energy-efficient window ratings and terms — Generally, the more energy-efficient and sturdy a window is, the higher its cost.27 However, the long-term savings you’ll experience throughout the life of your energy-efficient windows may offset the initial investment.28
- Ask about the window warranty — A warranty’s value is directly tied to the quality of the product it covers and the reliability of the company providing it.29
- Schedule a consultation to see the windows in person — Insist on examining full, working window samples so you can thoroughly inspect the window before it is installed in your home.30
For more detailed information, visit our window buying resource center for helpful downloads. Curious about where to purchase energy-efficient replacement windows for your home? Schedule your free, in-home estimate, or call us at 1-800-230-8301 for further assistance.