If you’re considering a new patio door or front door, you might be thinking about how to optimize its performance. The right glass can help with energy efficiency, noise reduction, and can even provide return on investment. But the right glass choice depends on your home, your climate, and other factors unique to your situation. Not to worry! We’re here to explain how to weigh these considerations and decide between double-pane and triple-pane glass for your new French door, sliding door, or entry door.
Double-pane (or dual-pane) glass and triple-pane glass are the two types of insulated glass units (IGUs) available with our products. An IGU includes panes of glass sealed together for increased energy efficiency. Here’s how to think about each:
| Double-pane glass: | Triple-pane glass: |
|---|---|
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*Products for high altitudes require capillary tubes, which are air filled. |
 A triple-pane IGU has three panes of glass and two air spaces in between them. Just like double-pane glass, the air spaces are filled with an argon-gas blend. In addition to our standard Low-E/Low-E4® coating, triple-pane glass allows for additional combinations of low-emissivity (Low-E) coatings inside the IGU. The additional air space and opportunity for more Low-E coatings are what make triple-pane the best performing glass. |
Very thin and generally transparent, Low-E coatings are added to window and door glass to improve energy efficiency. Low-E coatings are widely available in window and door products, but not all manufacturers offer it as a standard option. Dual-pane insulating glass with a Low-E coating is the default standard for all our window and door products.
We offer a variety of Low-E glass options, including our standard Low-E/Low-E4® glass, which is a good choice in climates where both heating and cooling costs are incurred. There are other options as well, including some that are ideal for hot and sunny climates, and some that are ideal for colder climates.
Dual-pane glass can have one coating inside the IGU, while triple-pane glass can have two coatings inside the IGU. Combining multiple Low-E coatings can provide even greater efficiency, which is part of the reason triple-pane glass performs so well. In addition to the Low-E coatings that are applied inside the IGU, there’s a Low-E coating that can be added on the interior (room-facing side) of both dual-pane glass and triple-pane glass. HeatLock® Technology is what it's called, and it can be very impactful.
Ready to deep dive into the details of Low-E coatings?
Feeling overwhelmed by these details? Remember, your pros can advise. Architects, builders, and window and door dealers specify and order windows every day. Lean on their expertise to help you make the right choices.
Triple-pane glass improves your door’s performance in the following ways:
This is due to the two air spaces filled with an argon-gas blend and the opportunity for multiple Low-E coatings. These features improve the insulating abilities of triple-pane when compared to double-pane glass. This level of performance is most needed in Northern climates, especially if there’s a desire to meet progressive energy requirements or build a high-performance home.
This is because of its thickness. When sound waves have to travel through multiple glass panes and multiple air spaces, they're slowed and effectively reduced. Triple-pane glass could be worth considering if you live near an airport, highway, etc.
Generally, triple-pane products cost more than double-pane products. Here’s what to know:
| Door cost (Double-pane glass < Triple-pane glass) |
Labor cost (Double-pane glass < Triple-pane glass) |
Energy savings (Double-pane glass < Triple-pane glass) |
|---|---|---|
| A door with standard double-pane glass will cost less than a door with triple-pane glass. Doors with triple-pane glass require more materials, including some that are heavier and take longer to produce, like the glass. With a thicker and heavier IGU, stronger and more expensive components are required. So the overall materials and manufacturing that go into the door make it a more expensive product. | A door with triple-pane glass will cost more to install than a door with standard double-pane glass. This is because it’ll be heavier, which equates to more labor hours needed, the potential for rental equipment, and other increases in expenses associated with installation. | A door with triple-pane glass will outperform a door with standard double-pane glass from an efficiency standpoint. A triple-pane door could decrease your energy costs over time, especially when integrated into a home that’s designed to use less energy, such as a passive home. |
TIP: We have a robust product portfolio to meet a range of budgets. When looking for a door with triple-pane glass that offers value without sacrificing design, don’t overlook the 200 Series Narroline® Gliding Patio Door. It has expansive glass and narrow framing for a modern look at a friendly price point.
There are several measures of thermal performance that can be helpful to use when trying to understand how your chosen door will perform or when comparing doors.
| If you live in a cold climate where you spend more on heating, you’ll be looking at U-Factor values |
If you live in a hot climate where you spend more on cooling, you’ll be looking at Solar Heath Gain Coefficient (SHGC) values |
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 U-Factor value measures the rate of heat loss through a material. In this case, through a door. It helps you understand how insulating a door is, and it’s measured on a scale from zero to one, with a lower number indicating better performance (less heat loss). If there’s an energy code in place where you live, it might require windows and doors meet a specific U-Factor value. |
 SHGC value measures how much energy from the sun passes through a material. So looking at a door’s SHGC value will help you understand how effective it is at keeping heat out of your home. It’s measured on a scale from zero to one, with a lower number indicating less solar energy entering through the door. |
Looking at U-Factor and SHGC values can become complex quickly. For example, a product that meets ENERGY STAR® performance requirements in the Northern climate zone could have a higher U-Factor value if it also has a higher SHGC value. This might be the right balance for a house that’s designed to be passive and actually use the sun’s energy to help with heating. When you get into this level of complexity, lean on your pro to help you evaluate products that’ll perform in a way that’s complementary to your home’s design and energy goals.
Wondering how the move from double-pane to triple-pane glass affects performance? Find U-Factor or SHGC values for the specific door you’re considering by looking up NFRC data for the series.
VLT is a measure of how much sunlight passes through a window or door. One drawback of triple-pane glass and Low-E coatings is that they can lower VLT, which is measured on a scale from zero to one with higher numbers indicating more light.
The change from double-pane glass to triple-pane glass can increase a door’s weight by 1 ½ times. Our doors with triple-pane glass include framing and components like hinges, sliding mechanisms, and rollers that are designed to perform properly, even with a weightier piece of glass.
When it comes to installation, the weight of the door might necessitate an extra pair of hands or rental equipment, which could increase labor costs.
Still unsure if double-pane or triple-pane glass is better for your new door? Let’s walk through the questions to ask yourself:
In a Northern climate, triple-pane glass provides more benefits. It’s not typically needed for higher performance in Southern climates.
If yes, triple-pane glass might make sense, but it’ll again depend on your climate. Find out more about doors and windows that meet ENERGY STAR® v. 7.0.
A front door or patio door with triple-pane glass will cost more than one with the standard dual-pane glass. However, we do offer products with triple-pane glass through several different product lines, including the value-oriented 200 Series. So it’s possible there’s a door with triple-pane glass that could fit a more limited budget. The best way to find out if a door with triple-pane glass is in your budget is to request a quote.
Good news here: Either a door with dual-pane or triple-pane glass could work as our doors are made of a variety of materials.
Dual-pane glass comes standard with our Entry Doors, Frenchwood® (hinged patio doors) and sliding glass doors (gliding patio doors), so you’ll have a variety of material options to choose from, including clad-wood and our composite Fibrex® material.
Triple-pane glass is available with doors from our clad-wood product lines, including A-Series, E-Series, Entry Doors, 400 Series, Big Doors, and 200 Series doors.
