Blog > Category > Posted: 2022-Jun-28, Updated: 2024-Jun-21

Energy Star product specification comparisons

When deciding where to buy your windows, finding comparative information is straightforward. However, interpreting this data can be overwhelming.

If window energy efficiency is a priority for you, the best resource is the Natural Resources Canada Energy Star Program. Their website provides up-to-date information on Energy Star-approved window products and detailed product results for comparison.

With nearly 100,000 window models listed, you can search by specific manufacturers and window models to find efficiency rating data.

Despite the abundance of technical information available, the specifications can be confusing. Different rating units are sometimes used, adding to the complexity.

To help you get started, focus on these key specifications: Energy Rating (ER), Solar Heat Gain Coefficient (SHGC), U-factor, and Visible Transmittance (VT). These metrics will give you a clear picture of a window’s energy performance. For more information on how to read ratings click on the links above or visit the individual blog post in the "Related Blog Posts" section at the end of this blog entry.

We also created a sample comparison sheet for some local products available in the Ottawa area, focusing on single-casement windows.

Our local sampling

To ensure clarity and understanding, our simplified example (from 2017 downloaded from the Natural Resources Canada website) was created using the Canadian Energy Star Most Efficient window supplier list. Current data is available at: Energy Star - Product Search

1. We filtered out:

  • Many of the manufacturers that don’t market themselves in the Ottawa area
  • Non-vinyl single casement windows
  • Windows that did not meet zone 1, 2 & 3 ratings
  • Excluded infill. Air Leakage L/s*m2 & Exfil. Air Leakage L/s*m2

2. Sorted the spreadsheet for the most efficient products/brands:

  • Energy rating
  • Solar heat gain
  • U-factor (Btu/h-ft2 F) & U-factor (W/m2 K)
  • Visible transmittance (VT)

3. Added green for the top 2 performers for each rating

The results

Filtering produced the best rankings for each manufacturer from the manufacturer’s list. The spreadsheet indicates the best ratings for each product shown.

Create and edit your own list


Replacing windows can seem daunting, but by doing your homework, you can balance energy efficiency, quality, and affordability. Focus on energy ratings when comparing products; reputable companies usually provide this information. Ensure you're comparing similar products accurately by double-checking specifications.

Choosing energy-efficient windows saves on energy bills and enhances home comfort. Don't settle for subpar options—with careful research, you can find the perfect windows to meet your needs and budget. Invest wisely in your home's future.


When shopping for products, thorough research and comparison are crucial to making informed decisions. This is especially true for home improvements like purchasing new windows or doors. Rather than being swayed by brand names or sales pitches, focus on the specifications and model numbers provided by the companies you're considering.

In this post, we aim to highlight the importance of examining the specifics, not endorsing any particular brand. By looking closely at model numbers and specifications, you can determine which products best meet your needs and requirements. With the right information and careful consideration, you can make a smart purchase that brings long-term satisfaction and value to your home.

What are window ratings?

CDN Energy Star Climate Zones

What are Energy Star energy ratings?

What is a U-factor?

What is the Solar Heat Gain Coefficient?

What is visual transmittance?

What is an R-value?

Infographic - Making windows energy-efficient

Infographic - ENERGY STAR labels & specifications

Need more information?

Upgrade to energy-efficient windows today and save on your energy bills while reducing your carbon footprint! Contact Bayview Windows to explore our range of Energy Star-rated windows and take the first step towards a more sustainable and cost-effective home.

Request information | 613-838-2211 | Request a quote