Most manufacturers have their name imprinted somewhere on the window, such as the spacer bar, hardware, or frame. Other manufacturers will include an identification number printed on the glass itself. If you’re unable to find either of these, then your window was manufactured locally (oftentimes called a “shop window”). 

With a manufacturer name (or even better, the identification number) you can attempt to research the information to find out when the product was made. Keep in mind this won’t tell you when the window was installed on your home, but can get you close.

While clean windows don't automatically increase home value, they make your home look more attractive from the outside, and since the exterior is the first thing a potential buyer will see, it can help make a good first impression that paints the rest of your home in a positive light. Educated homebuyers will see that your home is well cared for if they see clean window tracks and sparkling window glass, which can contribute to an overall positive opinion of your property. Clean windows give the impression that the rest of the home—including systems and appliances—is probably well-kept, too.

If your double-glazed windows are letting in a lot of noise, it might be because of improper installation. You may need to apply an acoustic caulk around the window to close any gaps or hire a window installation expert to fix the windows. Double-glazed windows are typically more effective at reducing noise when they have thicker glass panels or have a gas filling, like argon or krypton, between the two glass panels.

Yes, storm windows should be tempered. According to the International Association of Certified Home Inspectors, tempered glass is stronger and can withstand temperatures higher than laminated glass. Tempered glass is important for storm windows because it protects against outside elements and household accidents by not producing sharp, jagged pieces when it breaks or shatters.