Which Windows Are Most Energy Efficient? An Expert Guide to Save on Energy & Costs

When the time comes for window replacement, most homeowners prioritize energy efficiency. After all, choosing the right windows can dramatically improve comfort and lower your energy bills. But what actually makes a window energy efficient? There are a range of important factors to consider, and making a decision can quickly become overwhelming. Thankfully you have the Window Geeks on your side! We’ve taken over 40 years of experience and expertise and compiled a handy guide on how to choose energy-efficient windows.

What is the Best Window Frame Material for Energy Efficiency

There are a number of window frame materials to choose from, and the level of energy efficiency can vary considerably. Standards have changed greatly over time.

Wood Window Frame

Being a natural insulator, wood tends to offer good thermal performance. It does however require more upkeep and maintenance than other materials and absorbs moisture which can lead to swelling, decay, and rot.

Aluminum Window Frame

Aluminum, while durable, is a poor insulator compared to other window materials because of its high thermal conductivity. There’s a good reason homeowners have moved away from this material in recent times.

Vinyl Window Frame

Vinyl frames are excellent insulators because they have low thermal conductivity. They don't transfer heat or cold as easily as metal window frames. Many vinyl frames also have internal air chambers that help increase insulation.

Fibreglass Window Frame

Fibreglass frames are very efficient at insulating because they have low thermal conductivity and are highly resistant to expansion and contraction with temperature changes. The big downside is that they’re considerably more expensive than vinyl while only being slightly more efficient.

Energy-efficient window materials make a big difference! If you’re looking for superior efficiency at a reasonable price, vinyl windows are the way to go.

How Does Glazing Affect Window Efficiency and Insulation?

Gone are the days of single-pane windows (hooray!). Windows now have multiple panes with cavities filled with noble gases such as argon, offering much-improved thermal performance and comfort. Nowadays, homeowners have a choice: double or triple-pane windows?

Double-Pane Windows are significantly more efficient than their old single-pane counterparts, with the combination of extra glazing and a gas filling making homes far more comfortable. Double-pane windows have been the standard since the 1980s.

Triple-Pane Windows provide elevated efficiency thanks to the extra glass layer and gas-filled space, but they also come at an added cost. However, if you’re looking for rebate-qualifying windows, you’ll have more luck opting for triple-pane products.

Is triple-pane glass worth the extra cost? When it comes to the number of glass panes, there’s not an easy right answer. The choice depends on the specific needs of individual homeowners. Consult a trusted, reputable Window Expert who can help you determine which option is right for you.

What is the Role of Glass Coatings in Energy-Efficient Windows?

What’s the best window glass for energy savings? One of the biggest breakthroughs in improving window efficiency has been the introduction of glass coatings, which greatly improve window insulation ratings. These ultra-thin coatings, usually of a metallic material such as silver, are applied to the surface of the glass to limit the amount of infrared and ultraviolet light that can pass through the window. Reflecting this light back to its source prevents the transfer of heat, and this works both ways – keeping you warmer in winter and cooler in summer.

LoE1 is a single coating offering limited protection in terms of light and heat transfer. For some companies, this is the standard.

LoE2 has an extra coating providing improved protection and thermal performance. This is the base option for Centra’s windows.

LoE3 offers a triple coating which provides even more protection. LoE3 is a fantastic choice for windows with high levels of sun exposure, such as south-facing windows without shade.

LoE3 + i89 gives you a fourth coating, which can allow double-pane windows to perform like triple-pane windows. This is recommended in extreme climates that experience high heat or regular freezing temperatures, or if there are special concerns regarding UV rays.

Low emissivity coatings, or LoE coatings for short, have made a major difference for homeowners when combined with extra window panes and superior frame materials. More coatings come at extra expense, but they also help improve your home’s efficiency further.

What Type of Window Is Most Energy Efficient?

You may be looking at replacing an old sliding or casement window – or even cutting into the wall and adding a completely new one. You don’t necessarily have to replace like-for-like, and there are a number of window types to choose from – but which is the most energy-efficient?

Casement Windows: 4.5/5

Casement windows are hinged at the side and open outward. They provide a great seal when closed as the window sash presses so tightly against the frame, minimizing air leakage and improving insulation and overall thermal performance.

Awning Windows: 4/5

Awning windows are hinged at the top and open outward. Like casement windows, they also form a tight seal when closed, which helps prevent air leaks. They may not offer quite as much sealing pressure as casement windows because of their design, but they still perform very well in the energy efficiency department.

Sliding Windows: 3.5/5

Sliding windows consist of two sashes – one fixed, and one operable that slides horizontally. These windows can have more air leakage than casement or awning windows, but are also less expensive and can still be made highly efficient with extra panes and glass coatings.

Picture Windows: 5/5

Picture windows are fixed, meaning they don’t open at all. This means there should be no air leakage as long as the window remains intact. These windows should offer the best insulation especially when combined with high-performance glazing and a good frame material, but it’s unlikely you would want a home consisting solely of picture windows that can’t open.

When it comes to window replacement, don’t feel obligated to stick to what was there before. Consult with your Window Expert and see what options are available, and the pros and cons of each.

Why Does Product Quality Matter for Energy Efficiency?

Superior quality always means better performance, and it’s no different for windows. Are yours made by a company that takes quality and efficiency seriously, with a solid reputation for doing so? Are they designed and made locally for your climate, or shipped in from elsewhere? Are they custom-made for your home, or off-the-shelf products? Everyone is going to say they offer quality, but how can you truly know as a homeowner? Here are a few things to keep in mind when it comes to window replacement to ensure you’re getting top-quality products – and the fantastic energy efficiency boost that comes with them.

Years in the Industry

Experience matters! Find a company that has been around for a while. Longevity tends to equate to quality in terms of both products and service.

Customer Reviews

What do customers have to say about the company and the quality of their products, and do the reviews seem legitimate? Take some time to dive in and properly weigh reviews and testimonials.

Sourcing and Materials

Who does the window company partner with to get their materials and components? Do those companies also have a solid reputation, such as Cardinal Glass Industries?

Certifications and Testing

A lot goes into making windows and ensuring they meet efficiency standards. Not only is Centra Canada’s first window manufacturer to join the TEAP program, we also use the same windows in single-family homes that we use in large-scale building restoration and new construction projects. This sets us apart from most competitors and means that the windows we install in your home have been made to higher standards.

Window Warranty

A solid warranty ensures you're protected in case of defects or installation issues, safeguarding energy efficiency improvements and showing that a company truly stands behind the products it makes. Homeowners who choose Centra benefit from one of the best window warranties available!

When choosing the right company for your project, always do your research. Window replacement is a big decision, and one you definitely want to get right!

What are Some Other Important Window Considerations?

Energy efficiency is usually top of mind when looking for new windows, but it’s not the only thing to consider. We find that homeowners also like to take into account…

Noise reduction

Windows with high soundproofing qualities can make a big difference, especially in noisy neighbourhoods.

Home aesthetics

There’s plenty of choice in terms of window styles and colours, so be sure to get some inspiration and find something to complement your home's design.

Supporting local

Choosing a local manufacturer brings added benefits such as knowledge of the local climate and homeowner needs, as well as superior service.

Window rebates

Many energy-efficient windows qualify for window grants and rebates, helping reduce your upfront costs. Check out the Centra Rebate Calculator to see if you qualify!

Overall, it’s a lot to consider – but don’t fret! Centra is always here to help make sure you get the perfect windows for your home. Get in touch today for your free consultation!

Western Canada’s Top Choice for Windows & Doors

Have an upcoming window and door project? Reach out to the experts for a free consultation! If you have any questions regarding this topic or anything else to do with windows, contact a local Centra Employee Owner at 1-888-534-3333 or drop us an email at info@centra.ca. Follow us on Facebook and Instagram to stay up to date, and test your window knowledge on LinkedIn.