The gas between window panes, typically argon or krypton, acts as a barrier to heat transfer. This means it helps keep your home warmer in the winter and cooler in the summer by preventing heat from passing through the glass. This gas layer also reduces condensation by stabilizing the temperature across the window and helps minimize noise. Essentially, it’s all about improving energy efficiency and comfort while lowering those utility bills.

Casement windows can either be left or right opening, and every window manufacturer makes both so that you can choose which works best for your space. In many cases, you’ll want one left-opening and one right-opening casement window to sit on either side of a picture window or to act as the side panels in a bay window. Just remember that the direction is described from the curb. An FCL (from the curb left) hinges out to the left if you’re looking at the exterior of your home, and an FCR (from the curb right) hinges out to the right.

Steel windows are durable and last a long time, but not in all weather conditions. If you live near the ocean, these windows might not be the best choice, as the saltwater breeze can corrode the metal. Steel windows are also more expensive than other types of windows. However, with that high price point comes a sleek, distinctive design that many homeowners find appealing, especially for modern decor. You can also restore steel windows to get a longer lifespan from them, so they can last longer than vinyl, aluminum, and even wood.

To tell if a window is single or double-pane, focus on the edge. Double-pane windows have two glass layers separated by a spacer, which you can usually see around the edges. For single-pane windows, it’s just one sheet of glass. Another easy trick: shine a light at the window—single-pane glass reflects once, while double-pane glass reflects twice. Lastly, if you feel both sides of the glass on a cold day, double-paned windows will feel warmer because of the insulating gap between the panes.