Are Steel Windows Energy-Efficient?

Let’s face it, the windows you choose can make or break a home or commercial building. As one of the most important features of a house, windows are not only integral to the overall appearance of a home both on the interior and exterior, but they also play a key role in providing a comfortable living environment for families. For years, windows in buildings of all types have been constructed using a wide variety of materials in an attempt to find the option that is just right. This list includes materials such as wood, aluminum, and PVC, to name just a few.

As homeowners and developers have continued to search for the right material to optimize functionality and comfort, steel has come to the forefront. Today, many homes and buildings are being outfitted with steel windows as a result of the undeniable benefits of this material. In particular, steel is extremely durable, long-lasting, provides unmatched security, and can be customized to fit the style of a space seamlessly. One of the most important benefits of French Steel™ windows is the recent improvement in thermal technology allowing us to achieve energy efficiency compared with other materials.

What Is Energy Efficiency?

In today’s environmentally-focused world, “energy efficiency” is a common term used in a variety of settings. But what does it actually mean? Simply put, energy efficiency refers to using a lower quantity of energy in order to provide the same amount of energy as non-energy-efficient alternatives. You are likely familiar with the idea that using high-quality materials to insulate your home will effectively lower the amount of energy needed to heat or cool the house. It may come as no surprise that windows play a major role in the energy efficiency of a home or commercial building, serving as the dividing layer between the interior spaces and outdoor elements. In fact, it has been found that 25-30% of residential energy use for heating and cooling is a result of heat gain and heat loss through windows. When windows are not energy-efficient, this heat gain and loss results in greater energy use to create a comfortable environment in residential or commercial spaces. This in turn means higher energy bills.

So, what can you do? If you believe your windows are lacking in the energy efficiency department, there are really only two options: Attempt to update existing windows with energy-saving measures, or install new windows that have been specifically designed using energy-saving materials.

Steel Windows & Energy Efficiency

Falling into the category of most energy-efficient materials from which windows can be constructed is thermally broken steel. Steel, unlike wood and other materials, is incredibly strong and resistant to corrosion, decay, and rot. When corrosion or rot occurs in windows as a result of exposure to moisture and adverse weather, regular wear and tear, or other harsh conditions, cracking, warping, and other forms of damage can occur. When this happens, windows are incapable of providing an effective barrier to contain warm or cool air, allowing for outside air to enter your space, and interior conditioned air inside to escape to the outside. This significantly diminishes energy efficiency, forcing your heating and cooling systems to work harder and expend more energy than is necessary.

Installing steel windows can prevent this from happening altogether. Incredibly durable, steel is highly resistant to harmful elements such as corrosion, mold, vermin, and even damage from severe wind storms due to the strength of steel. This means that steel windows will not experience the cracking and warping that is common to other materials over time, which results in lower window energy efficiency and higher energy bills.

Additionally, to maximize the energy efficiency of steel windows, they should be customized to fit the climate where the property is located. The needs of a building during a harsh Wisconsin winter are not the same as those in humid Florida, therefore it is important that steel windows are custom-fit. A popular choice of steel windows that enhance energy efficiency is thermally broken steel windows. Thermally broken steel windows incorporate technology that creates a thermal barrier between the interior and exterior sides of the window and other components. Steel windows installed with thermally broken frames effectively prevent hot heat or cold air from moving through the steel. A “thermal break” therefore creates a barrier that maintains the desired temperature inside the home or commercial building.

How Much Can I Save With Energy-Efficient Windows?

While there are a number of factors that go into determining the exact amount installing energy-efficient windows will save, it has been estimated by the U.S. Department of Energy that replacing single-pane windows with more energy-efficient insulated glass windows can save between $126 to $465 annually for the average 3-bedroom home. Over ten years, that’s up to $4,650 of direct savings.

Steel windows and doors made with a thermal break are more expensive than standard models. It may not be useful or recommended to have a thermal break on every opening, or on any openings. Generally speaking, south of Washington, D.C. and east of Texas, a thermal break is not recommended unless the following conditions are present:

  • Higher altitudes of 3,000+ feet, where the winter temperatures may remain consistently below 30°F for two or more days.
  • Large areas of doors & windows–160 square feet or more–that receive direct, unshaded sun for three or more hours, facing due south or west.
  • Refrigerated steel & glass rooms such as wine rooms, wine cellars, or other conditions where the temperature inside the room will vary by more than 30°F from the outside of the room. An experienced HVAC engineer may be helpful in this regard as well, to assess the likely dew point averages expected in such an environment.

Understanding R-Values & U-Factors

As you begin your search for steel windows, you might be wondering how to compare the various options available on the market in terms of their energy efficiency. For this reason, it is important to understand R-values and U-factors. Very simply, R-values and U-factors are metrics used to evaluate energy efficiency. While the U-factor measures the amount of heat lost through a window or door unit, the R-value is the measurement of heat loss through a single material such as a panel of wood or sheet of glass. The lower the U-factor of an item, the lower the amount of heat loss.

When buying steel windows, consider using these units of measurement to determine which choice is most energy-efficient.


There is a lot of talk in the door and window industry about True Divided Lights (TDL) and Simulated Divided Lights (SDL). This refers to how the panes of glass are separated one from the other in a given door or window.

TDL is the look many architects prefer because it reflects the legacy design of early 20th-century architecture when individual panes of glass were “putty-glazed.” It gave a hand-made or cottage appearance to the doors and windows.

SDL windows are made with the appearance of individual panes of glass but are actually one large piece of insulated glass with grilles added to the glass surface and aluminum “spacers” placed in the glass and behind the grilles.

Other Benefits to Steel Windows

While the energy efficiency of steel windows is a great advantage, there are a number of other benefits to installing steel windows. Another major benefit is that steel windows offer maximum security. Unlike other materials that can be easily compromised, the strength of steel ensures that burglars cannot easily access the interior of your property. Additionally, steel windows are customizable, enabling you to adjust their appearance to fit the style of your space. Whether you own a vintage-style home or are building an ultra-modern office space, steel windows suit almost every property.

Energy-Efficient Steel Windows from The French Steel™ Company

As a leading provider of highly energy-efficient steel windows for homes and commercial buildings, The French Steel™ Company is standing by to help match you with top-quality windows that ultimately help you reduce energy bills while still enhancing the overall appearance of your space.

Contact a French Steel™ consultant today to discuss the importance of energy-efficient windows, how you could be maximizing the energy in your property, and the options available within your residential or commercial budget.

2022-10-28T03:33:50-04:00By |Steel Window Benefits, Energy Efficient Windows, Steel Windows|Comments Off on Are Steel Windows Energy-Efficient?

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