Welcome back to our series on understanding the components of your windows and doors! In this article, we’ll delve into the world of window sashes, exploring their types, functionality, and importance, especially in terms of egress (emergency exits). By the end, you’ll have a clear understanding of how to choose the right sash for your home.

What Is a Window Sash?

A window sash is the part of the window that holds the Insulated Glass Unit (IGU). It plays a crucial role in the overall functionality and safety of the window. The sash ensures that the IGU is securely in place and allows the window to open and close smoothly. In emergency situations, the ability to quickly and easily open a window can be lifesaving, making the choice of sash critical for egress.

Types of Window Sashes

Single-Hung Sash:

• Description: In a single-hung window, the bottom sash moves up and down while the top sash remains stationary.
• Pros: Cost-effective, simple design.
• Cons: Limited ventilation compared to other types and may not always meet egress requirements due to smaller openings.

Double-Hung Sash:

• Description: Both the top and bottom sashes can move up and down.
• Pros: Enhanced ventilation, easier to clean.
• Cons: Slightly more expensive than single-hung windows. However, they are often preferred for egress windows due to their larger openings and ease of operation.

Sliding Sash:

• Description: The sashes slide horizontally.
• Pros: Easy to operate, ideal for wide openings.
• Cons: Can be harder to clean from the outside. Sliding sashes are also a good option for egress windows because they provide a large, unobstructed opening.

Casement Sash:

• Description: Hinged at the side, the sash opens outward like a door.
• Pros: Excellent ventilation, easy to clean.
• Cons: Requires space outside to open fully. Casement sashes are highly effective for egress due to their wide openings and ease of use.

Awning Sash:

• Description: Hinged at the top, the sash opens outward from the bottom.
• Pros: Good ventilation, can be left open during rain.
• Cons: Limited size options. Awning windows may not always meet egress requirements because the operating arm can restrict the opening size.

Impact on Functionality and Ease of Use

• Ventilation: Different sashes offer varying levels of airflow. Double-hung and casement sashes provide excellent ventilation, while single-hung and sliding sashes offer more limited airflow.
• Ease of Cleaning: Double-hung and casement sashes are generally easier to clean, especially from the inside. Sliding and awning sashes may require more effort to clean the exterior.
• Energy Efficiency: The type of sash can impact the window's insulation properties. Casement and awning sashes tend to seal tightly, offering better energy efficiency compared to single-hung and sliding sashes.
• Safety and Egress: In emergency situations, the ability to quickly and easily open a window can be lifesaving. Double-hung, casement, and sliding sashes are often preferred for egress windows due to their larger openings and ease of operation.

Egress Requirements

The National Building Code 2010 has numerous references to egress in different sections that refer to various building types. Specifically, Part 9 of the National Building Code, Housing and Small Buildings, Section 9.9.10, addresses egress from bedrooms. Each bedroom must have at least one outside window or exterior door operable from the inside without the use of keys, tools, or special knowledge and without the removal of sashes or hardware. The window must provide an unobstructed opening of not less than 0.35 m² in area with no dimension less than 380 mm.

Learn more about egress here: What is Egress?

Choosing the Right Sash for Your Home

• Climate Considerations: In colder climates, sashes that seal tightly, like casement and awning, can help keep the cold out. In warmer climates, double-hung and sliding sashes can provide better ventilation.
• Energy Goals: If energy efficiency is a priority, consider sashes that offer a tight seal and good insulation properties, such as casement and awning sashes.
• Safety Needs: For homes with safety concerns, especially regarding egress, double-hung, casement, and sliding sashes are excellent choices.
• Aesthetic Preferences: The style of the sash should complement your home's design. Single-hung and double-hung sashes offer a classic look, while casement and sliding sashes provide a more modern appearance.

Conclusion

Understanding the different types of window sashes and their impact on functionality, ease of use, and safety is essential for making an informed decision. Whether you prioritize ventilation, energy efficiency, or safety, there is a sash type that will meet your needs.

Stay tuned for our next article, where we’ll explore the sash and its impact on window functionality and performance!