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5 Steps To Create The Most Energy-Efficient Replacement Windows

May 11th, 2023 | 10 min. read

5 Steps To Create The Most Energy-Efficient Replacement Windows

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Replacing your home’s windows is a big investment. Because of this, you want to ensure your new windows meet your needs for look, performance, and energy efficiency. 

Maybe you’ve noticed your windows letting in hot drafts during summer. Or maybe you feel like you’re getting a sunburn when you stand in front of your windows for too long. 

You know you need your replacement windows to protect your home’s interior and be as energy-efficient as possible. So, how do you do that? 

As a San Antonio window replacement company since 1989, Southwest Exteriors has helped thousands of homeowners design the perfect replacement windows for their homes.  

Whether you want the most customizable window, the least expensive window, or the most energy-efficient window, our purpose is to educate you on all your options and help guide you to the right solution for your home. 

If you want your replacement windows to be as energy efficient as possible, you must consider several crucial elements. 


5 Steps To Have The Most Energy-Efficient Windows

When designing your replacement windows, you must know what elements are important to you to create the perfect windows.

Consider the frame, glass type, additions, and other factors to make the most energy-efficient window possible. 

Here are five steps to ensure your replacement windows will be energy efficient.


Step #1: Select The Right Window Frame Material For You 

Choosing the right frame material is the first step in designing your replacement windows. You must consider the degree of efficiency you want and how you want your windows to look. 

Most, if not all, modern window frame materials have energy-efficient properties. Although, some have advantages over others depending on what you want. 

Let’s look at the most common window types and their energy-efficient qualities. 


Fiberglass windows are one of the most durable window types available. The greatest energy-efficient quality of these windows is their low conductivity.

This means they will not be a host or excess heat that could transfer into your home. They help repel that heat and make your home more insulated. 


Similar to fiberglass, vinyl windows also have low conductivity. Vinyl, made of polyvinyl chloride, is a plastic material. It repels heat simply because of its molecular structure. 

This means vinyl window frames will not hold onto external heat and transfer into your home. This makes these windows a flexible yet durable option for homes in all climates. 


Because aluminum is a metal, many associate it with conductivity. However, most modern high-quality aluminum window frames are manufactured with a higher-performing aluminum that is made to combat conductivity. 

They are also made with a spacer to help decrease the possibility of heat conduction. 

Aluminum windows are not the most energy-efficient window frame option out there. But they are one of the most affordable. 


Wood windows are the oldest window type of all time, proving their quality, durability, and longevity. 

Wood as a material is an incredible insulator. This means your home will be better protected against weather coming into your home and disrupting its internal temperature. Most wood frames are also coated to combat color fading, deterioration, and water infiltration. 


Clad windows are one of the best insulators for your home. Made with a wood frame and exterior cladding, they have an extra layer of protection and insulation. 

This makes clad windows incredibly durable against all kinds of harsh weather while also being a maximum insulator. 


Choosing the right frame material for your energy-efficient windows depends on your goals for style and performance. Nearly every window type is energy-efficient, but some have better-performing qualities than others. 

  • Fiberglass and vinyl windows are made to repel heat, so exterior heat will not transfer into your home. 
  • Wood and clad windows are excellent insulators, with clad windows having a slight leg up in this category. 

If you want your windows to be extremely insulating, choosing a wood or clad window will be the best option, though they are the most expensive. 

Fiberglass and vinyl are more affordable options but are still durable with insulating properties. 

Consider how much you want your windows to insulate your home and what you want them to look like, as design and aesthetics are a large portion of choosing the right window frame material. 


Schedule your commitment-free consultation today!


Step #2: Consider Who Manufactures The Window Glass

As you are vetting multiple windows, manufacturers, and companies to work with, one of the most important things to consider is who makes the glass of your windows. 

Cardinal Glass Industries is one of the leading manufacturers of high-quality and energy-efficient glass for replacement windows. The majority of window manufacturers on the market use Cardinal Glass for their windows. 

What makes Cardinal Glass the best? 

  1. It has a two-seal system, the first seal being a polyisobutylene seal
  2. The secondary glass seal is a silicon seal
  3. Cardinal window glass contains a stainless steel spacer
  4. Desiccant is used between the glass spacers to absorb moisture

Because of its longevity, popularity, and continuous technology in the glass industry, Cardinal Glass is the only glass you want for your energy-efficient replacement windows. 

When considering window types and companies to work with for your project, it’s important to ask about the glass and who manufactures the glass. If it isn’t Cardinal, you may want to look for other options. 


Step #3: Choose A Window With The Right Energy Ratings

Energy ratings tell you how windows protect against harmful solar rays, how much heat transfers through the glass, and how air can infiltrate through the windows. 

There are seven major energy ratings to understand to ensure you choose the best replacement window for you. 

  1. Solar Heat Gain Coefficient (SHGC): This measures the amount of solar heat that comes through a window, ranging from 0 – 1. The lower the number, the better.
  2. U-Factor: This measures how well a window can insulate. According to the U.S. Department of Energy, the U-Factor for windows generally ranges from 0.20 – 1.20. The lower the number, the better insulator the window is. 
  3. Visible Transmittance: Visible transmittance (VT) refers to the amount of visible light that penetrates through the window, measured from 0-1. The lower the number, the less light comes through the window. 
  4. Air Leakage: Also known as the air infiltration rating, this measures “how many cubic feet of air passes through a window per minute in relation to the size of the window,” according to a blog post by window manufacturer Marvin. The lower the air leakage rating, the less air passes through the window. 
  5. UV Percentage: This measures the percentage of UV rays that penetrate through the window. A window with a low UV percentage will block more UV rays. 
  6. Infrared Percentage: This is the percentage of infrared rays that penetrate through a window. The lower the infrared percentage, the fewer infrared rays penetrate through the window. 
  7. Condensation Resistance: The condensation resistance rating measures exactly how well the window is resistant to condensation, measured from 0-100. The higher the rating, the more resistant the window is to condensation. 

When selecting the right replacement window for you, look for a window with a low SHGC, U-factor, UV percentage, infrared percentage, and air leakage rating. This will ensure your window will not let in harmful rays that heat your home, and your home will be better insulated. 

Understanding these key energy ratings will help you to ask the right questions about your replacement windows and choose the most energy-efficient one for you. 


Step #4: Add Low-E Coatings Or Additional Tints

Because glass makes up more than 95% of a window, it plays the biggest role in energy efficiency. 

Most replacement windows are made with Low-E glass. But, some manufacturers offer the ability to add extra Low-E coatings to make the window more energy efficient. 

Low-E glass blocks UV and infrared rays, which heat your home. This means if you want a highly efficient window that blocks maximum heat and harmful rays, you will want to upgrade your window glass to have multiple Low-E coatings. 

Another addition you can make to your glass is adding glass tints. Tints will help block sunlight and heat from coming through your windows while also providing more shade. They are a perfect solution if you want to decrease the amount of light coming into your home while also keeping it cool. 

To make the most efficient replacement window, ensure the windows are made with Low-E glass and upgrade to additional Low-E coatings if possible. For more solar protection, consider adding tints to the glass. 


Step #5: Ensure Your Windows Are Installed Properly With A Trustworthy Contractor 

The final step to creating the most energy-efficient replacement windows is the installation. Even if you choose the highest-quality, most energy-efficient windows, they will not protect your home as they should if they are not installed correctly. 

Now, this doesn’t mean you have to be an expert on window installations. But knowing the basics of how a window should be removed and replaced and what materials should be used is crucial. 

Asking the right questions about what caulk is used, how the replacement windows are measured and removed, and what their processes are is important. 

You want to know your windows will fit your home perfectly and be sealed with a high-quality caulk that will last and protect your windows against drafts and water infiltration.

This means you must find the right window replacement company with great reviews, longevity in your area, and high-quality products and processes you can trust.


3 Steps To Find The Right Home Remodeling Contractor For You


Creating The Most Energy-Efficient Replacement Window For You

Now that you know the five key components of designing energy-efficient windows, you can continue your research in window types and contractor to find the best solutions for you. 

To create the best window for you, you first need to outline your wants, goals, and needs for your project. What do you want your windows to look like? How efficient do you want them to be? What is your budget? 

From here, you can consider these five things to create the most energy-efficient window: 

  1. Material of the window frame 
  2. Who manufactures the window glass
  3. The energy ratings of the glass
  4. Additional Low-E coatings
  5. The quality of the contractor 

With these five components of creating an energy-efficient window, you will know what type of window you need and can find the right company that can turn your dreams into a reality. 

When searching for the best energy-efficient window for your home, there are two key questions to consider to help you find the right window and contractor. 

Check out this article that outlines these two questions, why they are important to ask, and how the window will affect your home. 


Ready To Upgrade Your Old Windows With A Company You Can Trust? 

Southwest Exteriors has installed high-quality, energy-efficient windows for over 33 years. Our professional window installation teams treat you with compassion and replace your windows with care. 

If anything happens to your windows for as long as you own your home, we’ll be here to do all we can to make it right. 

Ready to elevate your home with new replacement windows? Schedule your commitment-free consultation with Southwest Exteriors today!