Casement Window

Casement windows open to the outside of the home via a crank handle and are typically hinged vertically at the side similar to how a door opens.

Casements are screened on the inside of the home and can be locked in open positions, which helps keep your home secure. They are typically operated via a crank for opening and closing and use a simple lever for locking.</p><p>More advanced casement windows such as Passive House grade windows can be hinged at multiple anchor points allowing for opening (toward the inside) of the window from the side, top, and bottom. These windows also use a simple handle with open and locked positions.

There are a few variations of casement windows. A French Casement Windows has two casement windows used side-by-side, hinged from the exterior sides, and the two windows can open similarly to a set of French doors. The term Double Casement Window is used to designate two casement windows that are placed side by side to create the look of one window divided in the middle.

Windows in general work against the efficiency of your home, so it's important to be strategic about their size and placement, and about the window fabrication itself. Higher grade windows, such as passive house windows, typically use three panes of glass, multiple gaskets and multiple latches, and low-emissivity (Low-E) coatings. The frame of the window is also important, with wood framing typically being the most efficient (but also the most expensive choice).

Like other window types, look for the Energy Star window rating label in North America as a starting point. It contains these factors for windows:

• U-value (inverse of R-value) measures how fast heat flows through, so lower U-value is better)
• Solar Heat Gain Coefficient (SHGC) measures how well the window transfers solar heat energy
• Air leakage (lower is better), and Energy Rating (ER - dimensionless) is a combination all those factors (higher ER is better).

Excellent U-values are around 1 W per sq. m per degree (equivalent to R5), and excellent ER ratings are above 35.

The sustainability of a window is largely tied to two things: resiliency and efficiency. That means choosing the best window means a window that will last a long time, and that helps you save money through better insulation value of the window. It all comes down to choosing the right placement and sizing of the window while choosing better materials to optimize the window's efficiency. Triple pane or quad pane, low-emissivity coatings, multiple gaskets, and latches, along with good air sealing and insulation values are what will ensure the casement window's energy efficiency.

The most basic window is, of course, simply a hole in the wall to let in light and air. Many different materials have been used over the centuries to fill window openings to let in light while keeping out insects, animals, rain, and wind. Before glass became widely manufactured, translucent materials including paper, animal hides, flattened animal horn, and even thin slices of marble were used as window panes.