Types of Glass for Windows: The Smart Buyer’s Guide to Saving Money and Energy

Types of Glass for Windows

Picking new window glass for your home is a big decision that can change how much energy your home uses, noise levels, cost, appearance, and durability. This article explains the most popular types of glass, key things to think about when picking, and tips to help you make the smartest choice. Investing in good glass can save cash overtime from using less energy.

Related: Best Glass for Double Glazing

Single Pane Glass

Single pane glass has one sheet of glass in the window frame. It does not insulate much.

  • Good Points: Single pane glass is usually the cheapest choice.
  • Bad Points: Almost twice as much heat is lost versus double pane glass. Single pane glass also does not block noise much. It tends to get condensation in cold weather.

Double Pane Glass

Double pane glass, used in most modern windows, has two sheets of glass separated by a gap of 1/8 to 3/8 inches. The air space provides more insulation than a single pane.

  • Good Points: Compared to single pane, double pane glass cuts energy bills 25-50% by sealing tighter. It also reduces noise coming through a lot. Repairs are not needed often, so it lasts longer.
  • Bad Points: It costs moderately more than single pane glass. Some fogging between the panes happens over time as the thermal seal wears down.

Low-Emissivity (Low-E) Glass

Low-E glass has a thin metallic oxide coating that blocks long-wave radiation transmission. This reduces summer heat gain and winter heat loss, keeping homes more comfortable. Low-E coats work on single or double panes.

  • Good Points: Beyond comfort, Low-E glass lowers bills by blocking UV rays that fade furniture. It has less inside surface condensation than plain double pane glass.
  • Bad Points: There is a moderate price jump versus no-coating double pane to buy the Low-E high-tech coating. Some minor outdoor glare can occur from reflected light.

Gas-Filled Glass

Gas-filled glass is like regular double pane glass. But instead of just air, the space between panes has gas – typically argon or krypton. These inert gases insulate better than air.

  • Good Points: Argon or krypton gas further improve insulation about 20-30% over air-filled double panes, cutting energy use. This glass also dampens outside noise more. Tight seals mean fewer long-term fogging troubles.
  • Bad Points: The complex manufacturing and the need for specialty gases increases costs over basic double pane glass. Rarely, gradual seal failure may cause gas leaks over time.

Smart Glass

Smart glass uses a special conductive coating that darkens when voltage is applied. It can switch from see-through to opaque instantly with the flip of a switch.

  • Good Points: Beyond others, smart glass provides adjustable privacy, blocks glare, and regulates temperature. You actively control how dark the tint gets.
  • Bad Points: It has a far higher price tag than other kinds of glass. The glass defaults back to clear if power is lost rather than staying dark.

Comparing Glass Options

  • Saving Energy: Gas-filled, Low-E > Double pane > Single pane
  • Blocking Noise: Smart, Gas-filled > Double pane > Single pane
  • Lasting Long: Double pane > Single pane
  • Cost: Single pane < Double pane with basic coating < Gas-filled, Low-E < Smart glass

No single glass type is perfect for everyone – factors like weather, noise, budget must be weighed to pick what works optimally.

Other Important Stuff to Think About

  • Climate & Direction: In cold areas with lots of heating days, focus on insulation with Low-E and gas. Account for sunlight based on direction – intense western sun needs effective afternoon shade.
  • Frame Type: Metal frames conduct more heat than wood, vinyl, and fibreglass. Match glass energy savings to total window performance.
  • Installation Quality: Good tight sealing maximises how well any glass works. Bad sealing causes leaks and lowers expected savings.
  • Appearance: Reflectance, visible light passed through, colour, and smoothness impact looks.

Bottom Line

The window glass picked has big effects on comfort, efficiency, longevity, appearance, and window expense over time. While basic double pane glass gives meaningful gains over old single pane at a moderate price, upgraded Low-E coats and gas fills insulate better. Smart glass allows adjustable tinting but remains expensive. Consider climate, noise, views, and budget to invest in the best long-term glass. Proper installation is crucial to meet expected energy savings too.


What is the best glass for reducing noise? 

Gas-filled double pane glass or smart glass offer the most effective noise dampening. Low frequency sound is challenging to block. But, advanced glass reduces mid to high pitched exterior noise. This is due to increased thermal insulation and mass.

How long does window glass last? 

Insulated double pane glass can last 20-30 years. This is with quality manufacturing and proper installation. It shouldn’t have significant issues like seal failure or fogging between panes. Protective coatings help maintain visibility over decades.

Which is cheaper, double pane or triple pane windows? 

Double pane glass is less costly than triple pane. It is the choice for consumers who want better efficiency than a single pane on a budget. Triple pane improves insulation. But, the returns diminish per investment. It is better suited for cold climates.

Does Low-E glass protect from UV rays? 

Yes, a key benefit of solar control Low-E coatings on glass is blocking over 75% of damaging UV light. It causes fading to interiors. Basic clear glass only filters around 25% of UV rays.

Can we retrofit smart glass to existing windows? 

Unfortunately, existing window frames lack the wiring and controls to alter the tint. Thus, they cannot retrofit smart glass to them. This advanced functionality would replace the full windows with integrated smart glass systems.

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