What Type of Window Is Most Energy Efficient?

Windows come in as many varieties as the houses they illuminate. However, just like houses, not all windows are created equal, and some are significantly more energy-efficient than others. Your windows’ energy efficiency should always be considered when upgrading or building your house for the first time.

In terms of windows that can open, casement windows perform the best to prevent air leakage, making them an excellent energy-efficient choice. However, consider the u-value of any window that you intend to purchase and the material it is constructed from. Those factors will also determine its overall energy efficiency.

As you might expect, choosing the right window for your home involves taking many different aspects into account. Something that you should review if you are planning to get your windows replaced.

What Should I Look For When Buying New Windows?

Buying new windows for your home is an excellent opportunity to improve your house’s overall energy efficiency and bring in a fresh feeling at the same time. The sheer amount of choices when buying windows can be daunting. However, taking the time to understand what each term and style of window really means for your home can go a long way in preparing you for making that major purchase.

The following is a break down of many of the more popular materials and styles available for the windows of your home. This list is not exhaustive, but it should give you an understanding of many of the factors that go into deciding the right windows for you.

Window Frames

This option may seem like a negligible one in terms of importance. Still, the frame that your window is housed in will significantly contribute to your house’s energy efficiency and determine the amount of maintenance required.

Aluminum & Metal Frames

Frames made of aluminum or other metals are expectedly very durable and require little to no maintenance regularly. Unfortunately, this type of frame also conducts heat very quickly, making it a poor insulating material choice. To make them as effective as possible, aluminum or metal-framed windows must include a thermal break between the interior and exterior of the frame and sash of the window that will help maintain insulation.

Wood Frames

Wood frames are the most traditional style of framing that has existed for hundreds of years. This material insulates exceptionally well but can require significant amounts of maintenance depending on climate and humidity. Generally, wood frames function better and require less maintenance in drier climates as there is less chance of mold and rot.

Fiberglass Frames

Fiberglass frames are a durable option that is thankfully not prone to warping and will also have air pockets that can optionally be filled with insulating material to improve their already impressive thermal properties.

Vinyl Frames

Window frames made of vinyl have excellent moisture resistance, which gives them a leg up in humid climates. Like their fiberglass counterparts, these frames’ hollow cavities can be filled with insulation, giving them even more excellent thermal resistance.

Glass & Glazing

Unlike the window frames of your house, which will likely be uniform due to climate and visual considerations, the glass inside those frames may differ depending on their orientation, environment, and building design. The glass and glazing you choose will significantly affect your home’s energy efficiency and should not be overlooked.

Insulated Panes

When shopping for new windows for your home, you will undoubtedly run across the term insulated more than once. For windows, insulated refers to windows that have two or more panes of glass that are spaced apart and hermetically sealed, which leaves an insulated air pocket between them.

Low-Emissivity Coatings

Low-emissivity coatings, commonly referred to as low-E coatings, lowers the u-factor of your windows, which translates to about a 30-50% greater energy efficiency than windows without this coating. The coating itself is a microscopically thin layer of metal or metallic oxide that is almost invisible. It is usually applied during manufacturing but is available in DIY kits for homeowners to apply to their existing windows as well.

Spectrally Selective Coatings

Technically speaking, this is another form of low-e coating. It is designed to filter out the infrared spectrum of light, which reduces the heat that transfers through your windows by 40-70% without compromising the visual spectrum of light. This style of glass coating is essential in scorching and sunny climates.

Gas Fills & Spacers

While this element may seem unusual, it is essentially an improvement to the double-pane spacing mentioned earlier. Instead of just using air between two glass layers as insulation, using inert, transparent, odorless, and non-toxic gasses like argon or krypton can offer tremendous insulative properties. Both options are excellent choices; however, it should be noted that krypton is the more expensive of the two.

Operation Style

The operating style of your window is simply the term used to describe if and how it opens and closes and in what manner it seals. Alongside the other factors mentioned above, the style of your window will contribute to its energy efficiency.

  • Fixed / Picture – This term describes windows that do not open or close. This style is notable because if it is installed correctly, it will be completely airtight.
  • Casement / Awning / Hopper – Each of these window styles are exceptional at sealing with minimal air leakage because the sash of the window closes by pressing against the frame. Each of these windows are hinged and swing open from the side, top, and bottom, respectively.
  • Single Sliding / Double Sliding – This style refers to windows where the sashes slide horizontally. There is only one sash that slides in a single sliding window, whereas both sashes slide in a double sliding window. While this style of window is prevalent in many homes, it suffers from significant air leakage due to the design of its sashes.
  • Single Hung / Double Hung – This window style is essentially the vertical version of the sliding variant listed above. Similar to that style, only the lower sash slides in the single variety, whereas both sashes slide in the double-hung variety. Also, these windows have significant air leakage issues like their counterparts.

Can I get a tax credit for installing energy-efficient windows?

Federal and municipal governments encourage many energy-efficient improvements to homes, which often leads to questions about whether tax credits are available for energy-efficient windows. While many places offer tax credits in differing amounts for these kinds of changes, it varies heavily from country to country and even from region to region within countries.

Reach out to your local or federal government to inquire whether you can earn tax credits for making energy-efficient upgrades to your windows. While these improvements can sometimes be costly, you can save money on your heating and cooling bills. If tax credits are available as well, that can further subsidize your costs.

A Breath of Fresh Air

Windows are a massive part of nearly every home on the planet. Taking the time to learn about the different options available to you when you are making upgrades to this essential feature will pay down the road fiscally and in terms of comfort. Whether you need to fix a single problematic window or you want to upgrade all of your fixtures, ensure that you have experts by your side every step of the way.

Check out our energy-efficient window solutions for your home and reach out to us with any questions or concerns that you might have.