Windows are a major component of a home. Window installation professionals will tell homeowners that the average life span of residential windows is between 15 and 30 years. Most well-maintained products can last 20 years, so homeowners who have windows approaching that age may want to schedule a window assessment and possible replacement.

Replacing windows is a job that requires advanced skill, and this is not a do-it-yourself project. There are many qualified professional window installation companies that will work with homeowners to measure, order and install windows that will fit with the style of a home and local weather, all while providing features the homeowner desires.

For those wondering when to replace windows, Pella and Renewal by Andersen, two of the premiere window manufacturers, offer these guidelines.

• Difficulty opening and closing windows. A window that does not operate as it should can aggravate homeowners. If windows are sticking shut or cannot be securely closed, it’s probably time for something new.

• There’s apparent window damage. Accidents happen, and if a rock is kicked up from a lawnmower and cracks a window or if spring baseball practice has gone awry with an errant throw, windows may require replacement.

• Drafts in the window are common. If heating and cooling systems are working overtime, drafty, poorly insulated windows could be to blame. Various agencies can perform energy efficiency tests in a home. Windows that are determined to be the weak spots should be replaced.

• Dated windows are present in the home. Older windows may pose safety hazards, especially those in older homes. A larger window may be needed to comply with fire safety codes allowing for window egress. Dated windows also may simply look “old” and compromise the aesthetics of a home.

• Outdoor noises are noticed quite readily. Newer windows can help reduce noise transmission. So those leaf blowers, airplanes, barking dogs, and kids playing basketball up the street won’t disturb homeowners as they try to enjoy some peace and quiet indoors.

• Fading indoors is noted. Windows that do not feature low-emissivity (Low-E) glass coatings will not block UV rays. Those rays can cause fading to wood floors and furniture or pretty much anything the sunlight touches. Replacing existing windows with Low-E coating alternatives can safeguard belongings and improve window efficiency.

Window replacement may be necessary when existing windows are showing signs of aging or damage.