Insulation is one of the most important considerations when choosing new windows for a home and good reasons. Your windows are one of the primary sources of energy loss in your home and making sure they are well insulated is a great way to keep your home more comfortable. Well-insulated windows also help keep your energy costs lower during the coldest months of the year.

Not all windows are created equal, some are better insulated than others, depending on the style. If insulation is important to you while you consider window replacement, we have ranked the most insulated windows based on their styles.

The Best Performing Insulated Windows Come at a Cost

When we say cost, we don’t necessarily mean money. The best-performing windows when it comes to insulating your home are those that don’t open at all. These types of windows include:

  • Picture windows
  • (Some) bay windows
  • Glass block windows
  • Arched windows
  • Circular windows
  • Transom windows

Not surprisingly, these fixed windows are the best for keeping your home warm because they are fully sealed. Since they do not open, there are no points where air can escape through a seal. These types of windows are the best way to let natural light into your home with as little heated air escaping as possible.

Hinged Windows: The Next Best Option

Windows that operate on a hinge are the next best option for insulation because, while designed for ventilation, they are much less likely to leak air than other window designs. These types of windows include:

  • Casement windows
  • Hopper windows
  • Awning windows
  • Egress windows

Hinged windows can limit the amount of heated air that leaks out of your home because they have a single window sash that the window presses firmly against. This single sash limits airflow while the window is closed.

A Good Option: Single Hung and Single Sliding Windows

The next on the list are single-hung and sliding windows. While these common windows can keep your home warm in the winter, they are less efficient than other types of windows because they contain two sashes on top of the windows not closing as firmly as their hinged counterparts. Because these types of windows open by sliding (either vertically or horizontally) they also have a break in the middle that can allow excess airflow. Having said all this, they are still a good option for keeping your home warm in the winter.

The Least Efficient Option: Double Hung and Double Sliding Windows

Double-hung and double-sliding windows differ from their single-style counterparts because they open from both ends of the window. Because of this ability, which is quite useful, these types of windows are the least efficient insulators. Double-hung and double-slider windows have three places where air can escape: one on each end of the window and one in the middle split of the window. They do insulate well, but they are the least efficient when compared to most other window styles.

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