Glazing density is among the important considerations when choosing a skylight. And when selecting between double or triple glazing options, several factors come into play.
First, it helps to understand what the term “glazing” refers to. Simply put, it describes how many panes of glass comprise the window part of a skylight. A “double-glazed” skylight has two panes of glass with a sealed air cavity between them (filled with a clear argon gas), while a “triple-glazed” model has three panels, resulting in an additional layer of insulation.
“Ultimately, the difference between double and triple-glazed windows comes down to an extra pane of glass, but that single pane can make a difference,” says Marco Ferrazzo, Process Manager with Artistic Skylight.
When it comes to glass, there is strength in numbers. Benefits of triple-glazing include:
- Higher efficiency: An added pane of glass provides the opportunity for additional low-emissivity (low-E) coating, which increases a skylight’s performance.
- Better insulation: Triple-glazing includes two insulating barriers that work together to keep heat from escaping an interior environment. This may not be much of a consideration in warmer climates, but it is relevant when adding a skylight to homes or buildings in cold Canadian regions.
- Money savings: Two pockets of insulation means less demand on heating systems which, in return, translates into energy savings and a lower environmental footprint. True, the percentage of energy savings might be in the low single digits, but every bit counts.
- Sound protection: Naturally, having an extra pane of glass between you and outdoor noises (e.g., neighbours, construction, traffic, etc.) helps to create a quieter environment.
Given the benefits, it can seem like triple-glazed is the easy choice when choosing a skylight. Still, the choice isn’t always so cut and dry. Adding another pane of glass comes with a slightly higher cost, and it is highly debated if those higher costs are paid back in cost savings.
“If your skylight is a smaller size with a small square footage, it may not be worth the extra budget to add a triple glazed unit,” says Ferrazzo, adding, “but as the square footage increases, so does heat loss, and the cost savings of triple glazed glass really start to break-even with the extra costs associated.”
It’s important to note that even Artistic Skylight’s domed shape acrylic skylights can also be configured with an added triple layer to meet both a higher thermal performance and more conservative budget threshold.
Picking between double or triple-glazed windows or skylights isn’t the most complex decision you’ll make during a renovation. Still, it’s one that requires at least some attention to factors such as insulation, noise, and aesthetics.
“There are a few things to keep in mind, but that’s where we can help customers figure out the model that fits best for their environment and budget,” adds Ferrazzo.