In most cases, you should get your windows cleaned one to two times annually, although you might want to complete this task more often if you live in an area with heavy pollen or heavy rain or snowfall that soils your windows. It’s also a good idea to hire a professional window cleaning service if you’re listing your property, as sparkling windows will make a big difference in terms of curb appeal and, potentially, your home’s value.

Replacing window glass instead of the entire window is more cost-effective, maintains the frame's aesthetics, and reduces waste. It improves insulation and energy efficiency and can be completed more quickly with minimal disruption to the home.

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.

Look for stickers at the top or inside of the frame, like in the tracks when the window is open. Some brands also stamp their name onto the frame itself or place it between the panes of glass, although this is less common. If you can’t find the info on the window itself, consider asking your neighbors or HOA.