Let’s talk about Windows

4 Elements Integrated Design
2 min readOct 8, 2021
Photo by Adeolu Eletu on Unsplash

Windows aren’t something you buy every day and we certainly didn’t learn about them in grade school. So how do you know which windows to buy? And how can you ensure that you have access to rebates offered by governments if you improve your windows thermal performance?

Window Ratings

Windows can be rated in two ways:

1. Using all the specifications of the window components such as U-value, Solar Heat Gain Co-efficient (SHGC), frame size, insulation type between panes, gas type, and low-emissive coating specifications.

2. According to the window’s Energy Rating (ER), which measures the performance of the window as a whole based on heat loss, solar heat gain, and air loss. The higher the ER value the better the performance.

It is worth noting that some manufacturers list both ways, some only list one way, and some may not list at all unless requested.

In cold climates Energy Advisors will always recommend a high R-value and a low U-value, but the ER number is a good base line for overall window performance.

The Greener Homes Grant program has prescribed metrics that need to be met for any rebate application. When you get your window quote there may be a lot of information that you don’t understand.

Reviewing your quote

Here are the 3 things you need to see on the window quote to ensure that all the individual windows are eligible for the grant.

1. U-Value. The numbers that each window must achieve are either

a. Less than 1.22 W/m2K (good) OR

b. Less than 1.05 (best)

2. The windows must be Energy Star certified on the Window Order and labelled on the window at installation.

Tip! Leave the Energy Star sticker on the window until the Energy Advisor comes back to very those are the windows you did in fact install, or they can not verify the label and you may not receive your rebate!

3. If there is an Energy Rating, it must achieve an Energy Rating of either:

a. More than 34ER, OR

b. More than 40 ER

You don’t need both the U-value and the ER rating, just one or the other, but in either circumstance you need to show the Energy Star certification on the window order and the Energy Star sticker on the physical window.

Lastly, check that your manufacturer and model number are on the approved Natural Resource Canada listing for Energy Efficiency Ratings (Windows):

You can also find a list of other Greener Home Grant requirements here:



4 Elements Integrated Design

Green Building Experts LEED for Homes Provider — Energy Advisors (ERS, ESNH, NZE) — R2000 Inspector — Built Green Verifier — ENERGY STAR Participant