Some homeowners are reluctantly putting off the decision to replace their windows because they’re not sure if they will recoup their initial investment. Still others are putting the decision off until they see what’s going to happen with the economy.

Is replacing your windows with energy-efficient windows really worth the investment? How much money replacement windows will save a homeowner depends, of course, on numerous factors. At the top of the list is the type of window you choose and there are plenty to choose from. There are single-panes, double-panes, and triple-panes. There are coated and uncoated windows. There are windows with hard coating and windows with soft coating. There are windows will gas filling and there are windows without gas filling. Some windows are filled with Argon, some are filled with Krypton. Decisions. Decisions. Where does a savvy homeowner begin?

You don’t need to be Einstein to deduce that dual-paned windows will save a homeowner more money on their energy bills than single-paned windows. But does the same hold true with triple-paned windows? Will triple-paned windows save you more money than dual-paned windows? Here’s what Energy Star, a government agency which promotes energy efficiency, says: “All energy efficient windows have at least two panes, but not all double-paned windows are energy efficient. Twenty years ago, double-paned meant energy efficient; today, advanced technologies have enabled the development of windows that are much more efficient than traditional clear-glass double-paned windows.”

Just as a dual-paned window is much more energy-efficient than a single-paned window, so also a triple-paned window is much more energy-efficient than a dual-paned window. But what are some of these “advanced technologies” that Energy Star is referring to?

There are four things to look for when choosing an energy-efficient window:

1. The layers of reflective glass coating.
2. The type of reflective glass coating.
3. The type of gas used between the window panes.
4. The U-Value of the window.

Once you find a triple-paned window that is manufactured by a reputable company, you have narrowed the playing field considerably. Now you need to consider whether the window panes are coated, how many layers of coating the manufacturer uses, and the type of coating they use. Some windows are coated with a reflective coating, while others are not. By selecting a window with coated glass, the coating will reflect unwanted cold in the winter and unwanted heat in the summer, thereby reducing your fuel costs and saving you money.

But not all reflective coating is created equal. Also bear in mind that most window manufacturers only coat one pane of glass. Few window manufacturers are willing to go the extra mile by coating two panes of glass. Naturally, this will increase the initial cost of the window. Nevertheless, this extra coating will usually pay for itself in savings many times over. Once you have found a triple-paned window that coats two panes of glass instead of just one, you will have eliminated most of the windows on the market. But your search for optimal energy efficiency is not quite complete yet. Patience, dear reader; we’re almost at the finish line.

The next thing to consider is whether or not the window manufacturer uses hard coating or soft coating. Soft coating is much better because it is more reflective. So why doesn’t every manufacturer use soft coating on their windows? Again, soft coating costs a little more. But investing a little more for soft coating will usually pay for itself many times over.

Insulation can be further improved by placing inert gas between the panes of glass. Some manufacturers use Krypton, most use Argon. Again, Krypton costs a bit more than Argon, but the extra savings that come from Krypton gas is well worth it.

The exact energy efficiency of a window can be scientifically measured by a trained window expert. It’s a smart idea to have a trained professional measure the energy efficiency of your current windows. Some say, “I don’t need to replace my windows. My home is just a few years old.” That may be true. However, some homebuilders try to cut costs by installing cheap windows that are not as energy-efficient as they could and should be. It’s better to be safe than sorry. Have an expert measure your windows for energy efficiency. Usually, there is no cost or obligation for this free service.

Once you’ve checked around and are ready to get a free estimate on your windows, be sure to ask the representative for the exact U-Value of the window you are considering. The official standard of measurement for energy efficiency is called a U-Value, also known as a U-Factor. The lower the U-Value, the more energy-efficient the window is. Here is a sampling of a few popular windows and their U-Values:

Alside (Vinyl): 6000 Double Hung 0.30

Alside (Vinyl): R601 Double Hung 0.33

Andersen (Wood): Woodwright (Low-E & Argon) 0.33

Preservation: 9001/P601 0.30

Anderson (Wood): A series Double hung 0.31

Marvin (Ultrex): Integrity (Low-E & Argon) 0.29

Marvin (Ultrex): Infinity (Low-E & Argon) 0.29

Pella (Wood): Proline (Low-E & Argon) 0.32

If you are considering replacing your windows with any of these popular brands, be sure to ask the representative these four following questions:

1. Do you use multiple layers of soft coating on two panes?
2. Do you fill those panes with a gas?
3. (If yes) Do you use Argon or Krypton gas filling?
4. What is the U-Value of your window?

The answer to the first three questions ultimately determines the U-Value of the window. Therefore, question number four is the most important. The U-Value will tell you how energy efficient a window is and give you an idea of how much money you’ll be able to save on your energy bills. The lower the U-Value, the greater a window’s resistance to heat flow and the better its insulating value. One window, though not as well-known as Andersen, Pella, or Marvin, has been able to achieve an incredibly low U-Value precisely because they follow the criteria mentioned in this article. Consider, for example, the U-Value of the Bristol Window, manufactured by Winchester Industries in Saltsburg, Pennsylvania:

Bristol (Reinforced Vinyl, overall window U-Value with Krypton): .18

Bristol (with Alpha-10): .21

According to the company’s literature, this particular window has been known to cut homeowner’s energy bills in half, though the exact savings will naturally vary depending on a wide variety of factors. A window expert can test your windows to find out whether or not they need to be replaced and calculate approximately how much money you will save if your windows do need replacing. By comparing the amount of money a window costs with the amount of money you will save, simple math will determine whether or not it is cost-efficient to replace your windows.

Another thing to consider is a window’s warranty. While most windows are only made to last for approximately 10 years, Bristol windows come with a transferrable 50 year warranty. That’s a huge difference. Instead of replacing your windows 5 times over the next 50 years, you can save additional money by only replacing your windows once.

Look at it this way: The government is giving you a huge head start. One thousand five hundred dollars is nothing to sneeze at. Now consider all the money you will probably save in the meantime. Often, the savings alone will pay for the windows within a few short years. It’s smart to have an energy expert help you do the math. If you still live in a home with energy wasting windows, you will pay for windows whether you replace them or not. The question is, would you rather pay extra money to your utility company for energy-deficient windows? Or would you rather invest in your home’s future value while dramatically reducing your energy bills by replacing your windows with energy-efficient windows? The choice is yours.