Of course, each situation will be as unique as the home in which it occurs - and as individual as the homeowners themselves. A few good rules of thumb, however, do apply in most cases. When you're considering repair or replacement, ask yourself these questions:
* How old is the malfunctioning item?
* How extensive/pervasive is the problem?
* Will the cost of repair approach the cost of replacement?
* Which course - repair or replace - will yield the maximum energy efficiency?
* How does the cost of repair measure up to the value it will provide? How does replacement stack up using the same measure?
To help you get an idea of how these rules apply, here's what some experts have to say about home elements that frequently raise the repair/replace question:
Skylights
While many modern skylights are energy-efficient, qualify to use the Energy Star mark and are leak-free, if you have an older, plastic model it's probably a good idea to replace it. Not only are these older plastic bubble-type skylights often faded and unsightly, reducing visibility, they are not UV resistant, are not energy efficient, and are much more likely to leak.
"There are millions of those unattractive, cracked and yellowed plastic skylights still out there," says Ross Vandermark, national product manager of VELUX America, which markets the warranted "No-Leak Skylight." "Replacing them with new energy-efficient, double-pane (insulating) glass models is quick and easy. They don't leak, they look better, they reduce UV rays and provide substantial energy savings."
In fact, based on an estimate of 15 cents per kwh/hr, replacing an old plastic skylight with an Energy Star-qualified VELUX skylight can save a 2,000-square-foot home about $194 a year on cooling costs, a company study shows. Add skylight blinds - which are available in a variety of styles that can be remote-controlled, including blackout to block light, light filtering to diffuse light, or Venetian to adjust light - and the energy savings can be enhanced even more. And blinds in colors and patterns can add a fresh look to your room decor. What's more, depending on the age and condition of even older glass skylights, it's not a bad idea to consider a modern, more energy efficient model. To learn more about replacement skylights, visit www.veluxusa.com.
Windows
Recent research shows that skylights and vertical windows can work well together to effectively daylight a home while contributing to heating and cooling energy savings.
Like skylights, windows have vastly improved in energy efficiency over the past few decades. Leaky, inefficient windows can be a major source of heat loss in a home, boosting energy bills and decreasing the comfort level indoors. Window manufacturer Pella points to these signs that old windows need to be replaced:
* They're difficult to open or close.
* You can feel air leaking in or out around them.
* Condensation or fogging occurs on or between glass panes.
* You can see chipping, deterioration or water stains on the window or the wall around it.
* Cleaning is a major chore and you avoid it because of the difficulty.
* It's difficult or impossible to find replacement parts for the old windows.
The Efficient Windows Collaborative (www.efficientwindows.org) site also provides extensive information on selecting both windows and skylights, including fact sheets and computer simulations for typical houses using a variety of windows in a number of U.S. cities.
Heating, ventilation and air cooling
Furnaces and air conditioning units are among the most important parts of your home's infrastructure; they're directly responsible for the comfort level and air quality inside your home. They're also among the more costly items to repair or replace.
So how do you know when it's time to replace part of your heating, ventilation and air conditioning (HVAC) system? EnergyStar.gov offers these guidelines:
* If your heat pump or air conditioner is older than 10 years.
* Your furnace or boiler is more than 15 years old.
* Your energy bills are spiking.
* Equipment needs frequent repair.
* Some rooms are too hot while others are too cold.
* The HVAC system is very noisy.
* Your home is very dusty.
Replacing older HVAC systems with newer, Energy Star-qualified ones can significantly impact your heating and cooling costs, according to EnergyStar.gov. An Energy Star-qualified heat pump or AC unit can save up to 20 percent on heating and cooling costs, the website says. You can learn more at www.energystar.gov.