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The Ultimate Glossary of Window Replacement Terminology

Understanding the wide variety of window replacement terms can be difficult for an individual who doesn’t work in this industry. From the different types of windows to the individual features and parts of windows, the whirlwind of information can quickly become overwhelming. 

At Green Energy of San Antonio, our team helps our customers understand the window replacement process every day. In this post from the Green Energy of San Antonio blog, we’ve put together a complete and comprehensive glossary of all of the window replacement terms out there. 

Window Replacement Hardware 

Window Sash 

Window sashes are the part of windows that surround the glass, holding it in place within the window frame. In some cases, window sashes are moveable, allowing the glass to slide up and down the track where it’s positioned. Not all window sashes can be moved, but most residential windows feature movable sashes. 

Window Frame 

Window frames are the framework surrounding and supporting the entire window system. Window frames are composed of several parts, including 

  • Head: A horizontal piece at the top of the window frame¬†
  • Sill: A horizontal piece at the bottom of the window frame, sometimes also called the stool¬†
  • Jambs: Vertical sides on the sides of a window frame¬†
  • Weep holes: Openings built into the bottom of vinyl and metal window frames that allow precipitation collected in the window tracks to drain out efficiently


A window lock is a mechanism that is used to secure the window in a closed or open position. Window locks are typically found on either the window frame or the window sash. In some cases, window locks can be operated by a key, but a lever or a handle most often controls them. 


Window handles are designed to open or close a window. Similar to a window lock, window handles are typically found on the window frame or sash. Handles can have built-in locks, typically paired with keys. 

Window Balance 

A window balance is a spring-loaded device used to counterbalance the weight of the window sash. Window balances allow windows to be opened and closed with minimal effort. Window balances are usually found on a track above the window, and then connected via a rod or cable. Then, the balance is adjusted by the window replacement professional to allow for smooth operation of the window. 


Window latches are the standard type of lock found on a single or double-hung window. The simple mechanism of a window latch connects the two sashes of the window and prevents either side from moving. 


Hinges are used to attach the window sash to the window frame. Window hinges allow window sashes to open and close, and can be adjusted during installation to provide a snug fit. Hinges are usually on the side of the window frame and can be either single or double hinges. 

Window Guide

Window guides are devices used to keep the window sash in place when it is opened or closed. In most cases, window guides are found on the side of the window frame, and help guide the window sash along the track. Window guides are a critical part of the window as it helps them from becoming misaligned or stuck. 

Window Installation Terms


Window caulking is a water-resistant material used to seal gaps and joints between the window frame and other building materials. Caulking is typically used around windows to prevent air and water leakage. Caulking is applied by filling the gap or joint with a sealant, such as silicone or acrylic, and then smoothing it out to ensure total coverage 

Insulating Glass

Insulating glass is glass used for windows that is designed to hinder substantial heat transfer from inside or outside of a building. It comprises several glass window panes partitioned by spacers composed of aluminum or structural foam to provide better heating and cooling retention for homes and businesses.


Window weatherstripping is a material or a set of materials that are used to seal gaps or spaces around a window to prevent the entry of outside air, moisture, dust, and other elements. The weatherstripping is usually made of materials such as rubber, foam, or felt and is installed on the movable parts of the window, such as the sash, to create a tight seal when the window is closed. 


Window shimming is the process of adding thin pieces of material, usually wedge-shaped, to fill any gaps between a window frame and the rough opening in a wall or window frame. The shims are used to level and secure the window within the opening, ensuring that the window operates correctly and is properly sealed against air and water leaks. 


Double-hung and slider windows may be equipped with an interlock system that enables the sash frames to engage and pull tightly together along their interface, thereby reducing air leakage. Interlocking is typically a feature found in higher-end windows. 

Window Replacement Materials


Glass is the primary material used in windows to allow natural light to enter a building while also providing a barrier against the outdoor elements. Typically, windows consist of one or more sheets of glass that are held in place by a frame. 


Vinyl is a common material used in the construction of window frames. Vinyl window frames are made from polyvinyl chloride (PVC), a synthetic plastic polymer that is lightweight, durable, and easy to maintain. Vinyl window frames offer several advantages over other materials, including good insulation properties, low maintenance requirements, and affordability. They are also available in a wide range of colors and styles, making them a popular choice for both modern and traditional homes. 

Types of Windows


Casement windows have a hinged sash that opens outward from the side of the window frame. This type of window can be operated using a hand-crank mechanism, which is typically located at the bottom of the window frame. By turning the crank, the window sash opens outward, allowing for maximum ventilation and fresh air to flow into the room. They are an excellent option for dining areas, kitchens, and bathrooms. 

Slider window


Slider windows, also known as sliding or horizontal windows, slide open on a track from side to side, making them a suitable option for areas with limited space that cannot accommodate outward swinging windows. The sleek design and clean lines of slider windows make them a popular choice for modern homes.


Awning windows are a type of window that is hinged at the top and opens outward from the bottom, creating an awning-like effect. This type of window is typically operated using a hand-crank mechanism that allows the window to be easily opened and closed. Awning windows are commonly used in basements, bathrooms, and other areas where privacy is important, as the outward-opening design allows for ventilation without sacrificing privacy. 

Single Hung 

Single-hung windows are a type of window that features two sashes, with one sash being fixed and the other being operable and able to slide up and down. The fixed sash is typically located on the top portion of the window, while the operable sash is located on the bottom. This type of window can provide ventilation through the lower sash, which can be raised to allow for airflow. However, the upper sash remains fixed and cannot be opened. 

Double Hung

A double-hung window consists of two movable sashes that slide up and down, offering flexibility in choosing the direction of the airflow. These windows can also be tilted inward for easy cleaning. They are well-suited for rooms where ventilation is crucial and are particularly convenient for upper-level rooms as they can be easily cleaned from the inside. Double-hung windows are a versatile choice that can enhance any room.

Picture window


Picture windows are designed to be fixed and cannot be opened or closed. As a result, they provide an unobstructed and stunning view that is unmatched by other types of windows. Picture windows consist of a large and durable glass pane that is encased in a sturdy frame. They are particularly ideal for areas such as dining rooms and kitchens where a picturesque view can add to the ambiance of the space. Cleaning picture windows is also very easy, as it only requires a quick wipe of the interior and exterior surfaces.


Specialty windows are a type of window that are customized to fit specific shapes, sizes, and design preferences. These windows are often used to add a unique and visually appealing element to a room or building, and they can be designed in a variety of shapes and styles, including circular, triangular, hexagonal, or arched shapes. Specialty windows can add character and charm to any space, and they are often used as a focal point in a room or as an architectural feature of a building. They are a popular choice for homeowners and designers looking to create a one-of-a-kind look for their space.

Green Energy of San Antonio is The #1 Choice For Window Replacement in San Antonio 

Green Energy of San Antonio is proud to be a top provider of replacement windows in San Antonio and the surrounding areas. Our team has the knowledge and experience required to successfully replace or install windows of several different types and sizes to improve the comfort and energy efficiency of homes in San Antonio. To learn more about our San Antonio window replacement services, or to schedule a free estimate, contact us online or over the phone today.