Complete Guide to Energy Efficient Windows (2022): Options, Installation & More
In this guide, you’ll learn:
- What are energy-efficient windows?
- What are the benefits of energy-efficient windows?
- What energy-efficient window options are there?
- What do energy-efficient windows cost?
- And much more
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Jump To: What Are Energy-Efficient Windows? | Benefits of Energy-Efficient Windows | Energy-Efficient Window Options | What Do Energy-Efficient Windows Cost? | How to Tell If You Need Energy-Efficient Windows | FAQ: Energy-Efficient Windows
What Are Energy-Efficient Windows?
Energy-efficient windows are those that improve the energy efficiency of your home. Specifically, they provide greater insulation than standard windows, which means there will be less heat transfer between your living space and the exterior of your home — that is, less heat transfer from inside to outside in winter and from outside to inside in summer.
There are many different energy-efficient window options, which we’ll discuss further below. For now, it’s useful to know that “energy efficient” is a somewhat subjective term, so it’s helpful to use standardized measurements, including U-Factor, which estimates insulative properties and solar heat gain coefficient (SHGC), which estimates heat loss.
There are governmental agencies that rate windows and make choosing energy-efficient options easier for homeowners. For example, windows can come with an Energy Star rating, which is issued by the U.S. Department of Energy and the U.S. Environmental Protection Agency. Windows with an Energy Star rating are guaranteed to conform to efficiency standards set forth by both agencies.1 The National Fenestration Ratings Council (NFRC) is a nonprofit that rates efficiency levels of windows and uses its own NFRC rating.2
For your purposes, you can think of energy-efficient windows as those that provide better protection from the elements, which in turn means that your energy bills will be lower, and you’ll put less strain on your heating and cooling systems.
Benefits of Energy-Efficient Windows
Energy-efficient windows are wildly popular today because they have several advantages over less-efficient options. We’ll discuss some of the most appealing benefits of energy-efficient windows below.
The most significant benefit to installing energy-efficient windows will, of course, be the boost to energy efficiency.3 These windows typically have more-insulative window frame materials that provide better protection from exterior temperatures. Some have voids that you can fill with insulation for even greater protection.
The glass in energy-efficient windows also tends to be layered. In the case of a double-pane window — also called a dual-pane window — there are two layers of glass with spacers and a layer of insulative gas — usually krypton or argon gas — sandwiched between them.
Triple-pane windows consist of three panes of glass with two compartments with gas fills. The double- and triple-layer protection means a much lower rate of heat transfer between your interior space and the outside, resulting in much better thermal protection.
The benefits of increased energy efficiency are manifold. First, you’ll experience lower energy bills because your heating and cooling systems won’t have to work as hard to keep your home comfortable. Second, since your heating and cooling systems aren’t working as hard, you’ll experience fewer outages and have fewer maintenance issues, resulting in lower repair and replacement costs. Finally, your home will tend to be more comfortable, as energy-efficient windows keep out drafts and uncomfortable outdoor temperatures.
Improved Noise Reduction
A benefit of energy-efficient windows many homeowners forget is the improved insulation from noise. Each layer of glass you add to your windows means another layer of protection from outdoor noise like landscaping equipment, road noise, air traffic and more.
Since energy-efficient windows typically have two or three layers of glass, they’ll keep your home quieter than windows with just a single layer.
Fewer Problems with Condensation
Homeowners with single-pane windows have likely experienced condensation on their window glass, which can be a nuisance and even cause damage. When one face of a glass pane is at a higher or lower temperature than the other, the moisture in the air on the warmer side will condense on the cool glass. The result is a foggy window that obstructs your view of the outside.
The worst part of window condensation is that it can accumulate and drip inside your home, potentially causing damage to your window frames, flooring, furniture or other belongings.
Double- and triple-pane glass windows rarely have issues with condensation, as the second and third layers of glass and the gas in between act as an additional buffer that prevents this problem.
Energy-Efficient Window Options
As we mentioned above, the term “energy-efficient windows” can really apply to many different things, and it’s a rather general term that describes a window with superior insulative qualities to single-pane and inefficient windows. Below, we’ll discuss some of the components that make energy-efficient windows efficient.
Here’s a quick overview of energy-efficient windows:
Glazing or Glass Type
Glass type is one of the most important aspects of energy efficiency in windows. Glass allows natural light into your home and breaks up the monotony of a solid interior or exterior wall, but it’s far less insulative than the materials that make a wall, so windows are where homes lose much of their energy. The type of glass you have in your windows can make a big difference in terms of energy efficiency.
There are three primary types of glass available for home windows: single-pane, double-pane and triple-pane.
Single-pane windows have just a single sheet of glass. They are the least efficient but most affordable type of windows by far.
Double-pane windows have two panes of glass with a sealed compartment between them containing an insulative gas —usually argon. Double-pane windows are generally considered energy-efficient, but keep in mind that other factors besides glass type go into overall window efficiency.
Triple-pane windows have three panes of glass and two layers of insulative gas sealed between them. These windows are generally the most energy-efficient, but again, just having triple-pane glass doesn’t automatically make a window efficient. Triple-pane window costs are usually just under double the price of double-pane windows.
The frame material is another crucial piece of the window efficiency puzzle. Window frames are typically made from one of five materials: aluminum, vinyl, wood, composite or fiberglass.
Aluminum window frames are the least energy-efficient, but they’re also the most affordable. They require very little maintenance and can be painted to suit your preference.
Vinyl window frames are much more energy-efficient than aluminum, and they’re only slightly more expensive on average. Some vinyl frames include voids that you can fill with insulation for better thermal protection. Vinyl cannot be painted.
Wood window frames are less energy-efficient than insulated vinyl, and they’re more expensive. Most homeowners choose them for their durability and aesthetic appeal.
Composite windows are made from multiple materials that offer the appearance of wood frames with superior energy efficiency. They are more expensive than aluminum, vinyl and wood windows.
Fiberglass is the most energy-efficient and durable window frame material but also the most expensive.4
Remember, one energy-efficient attribute — like window frame material — doesn’t automatically make a window energy efficient. For example, a fiberglass frame with a single pane of glass might not be an Energy Star-certified window, while an aluminum frame with triple-pane glass might.
Glass Coatings and Treatments
Modern windows can be coated or treated to improve energy efficiency and maximize energy savings. Two popular options are low-emissivity coatings (Low-E coatings) and window tinting.
Low-e glass coatings help reduce the amount of UV (ultraviolet) radiation coming through your window, and they also reduce the rate of energy loss through your window glass.5 These coatings can be applied directly by the manufacturer, but they can also be applied on windows that are already installed as an add-on for energy efficiency. Some Low-E coatings are selective, meaning they prohibit harmful UV rays but still allow ample visible light in.
Window tinting acts similarly, although it only reduces the amount of sunlight coming into your home. Window tinting can also be applied as a part of the manufacturing process or after the window is installed as an after-market add-on. Window tinting is popular in areas with intense sunlight that can cause UV damage and fade furniture, flooring and other belongings.
What Do Energy-Efficient Windows Cost?
It’s challenging to say what energy-efficient windows will cost because windows with the Energy Star rating that are considered to be energy efficient can vary quite a lot in frame material, glass type and glass coatings.
With that being said, the average cost for an energy-efficient window is around $450, and most homeowners pay between $325 and $1,000 per energy-efficient window. Since the price ranges so widely, we’ll break down the average costs for different energy-efficient window options below.
|Window Type/Option||Average Price Per Window|
|Vinyl window frame||$450|
|Composite window frame||$800|
|Fiberglass window frame||$1,000|
|Low-E coating||$6 per sq ft|
|Window tinting||$7 per sq ft|
This isn’t an exhaustive menu of options. There may be additional energy-efficient elements that can add to or reduce the price of your windows.
How to Tell If You Need Energy-Efficient Windows
Upgrading to energy-efficient windows is usually a good option for homeowners to improve their home’s efficiency, but many people don’t know when energy-efficient windows are a necessity. Below, we’ll include some warning signs that you should consider upgrading to energy-efficient windows.
- High energy bills: If you notice that your energy consumption or your utility bill charges increase year over year, it might be a good time to replace your existing windows with energy-efficient ones. Poorly insulated windows allow significant heat transfer with the outside, which means you’ll put more strain on your heating and cooling equipment and have a less comfortable living space.
- Drafts: Some of the biggest complaints from homeowners with poorly insulated or aging windows involve drafts in the winter. If you notice air leakage around your windows, you should immediately consider new windows that reduce heat transfer to and from the outside.
- Windows are hot or cold to the touch: If you touch the interior of your window glass in the summer or winter and it feels hot or cold to the touch, it means the glass is readily transferring heat. Consider replacing your windows with double- or triple-pane glass for improved insulation.
- Aging windows: Finally, if you know your windows are close to or over 20 years old, or you’re experiencing issues like poor operation, it might be time for replacement windows. Choosing energy-efficient options is best for improving your home’s efficiency and keeping energy costs to a minimum.
FAQ: Energy-Efficient Windows
The term “energy efficient” refers to windows that are highly insulative and have superior energy performance, meaning they have components that prevent heat transfer between your living space and the exterior of your home. There are several things that go into making an energy-efficient window, including frame material, glass type and glass coatings. Whether a window is energy efficient is subjective, but there are standards for efficiency set forth by the U,S. Department of Energy and the U.S. Environmental Protection Agency. Windows that match or exceed these standards are labeled with an Energy Star rating.
The most efficient window will have a fiberglass frame — which is the most insulative frame material — triple-pane glass, a Low-E coating and window tinting. Other energy-efficient options include vinyl and composite window frames and double-pane glass. As far as brands go, some of the most trusted energy-efficient options include windows from Andersen, Pella, Marvin, and Milgard.
For most homeowners, energy-efficient windows are well worth the investment. These windows improve the value of your home, and they also reduce your energy costs and make your home feel more comfortable. Energy-efficient windows are also becoming more and more affordable, which means you can enjoy these benefits without spending tens of thousands of dollars replacing your windows.