How can dual-pane windows be noisier than single panes?

[Perry]

I recently replaced my single-pane windows with a dual-pane style.

However, noise from outside seems louder than before.

Why would this be?

[home improvement guy]

You're right to wonder about this. Double-paned windows generally provide better sound insulation than do single-pane versions. So if that's not happening for you, quality issues may be the reason.

For instance, a high-quality single-paned window might outperform a poor quality double-paned version. You get what you pay for when it comes to windows, as with most anything.

If your new windows are of good quality, however, poor installation may be the problem. Noise enters from around a window, not just through the glass. Poorly measured windows may create gaps. Also, the amount of caulking or foam insulation a contractor places around the window will affect the level of sound blockage.

Other factors that influence noise insulation:

■ The type of material that surrounds the window, whether wood, glass or metal. Metal is a lower-end insulator; wood and vinyl are better options, though wood requires more maintenance.

■ What's between the panes. For instance, argon and krypton gas — commonly used to fill space between panes — are denser than air and block noise more effectively.

■ Window treatments and the presence of storm windows.

For the best sound control, as well as higher energy efficiency, choose windows with more space between panes or even an additional pane. Triple-paned windows, which cost about 20 percent more than double-paned, increase the energy efficiency of the glass surface up to 50 percent.

Each double-paned window, installed, costs $350 to $500. For an average home, installation of new windows may take about two days. Top-rated window companies say you should plan about a month ahead for installation, to give the company time to measure and make the windows.

When considering what window company to hire, be wary of too-good-to-be-true prices, as they may not include installation costs or the price of screens or other window components. Avoid companies that apply high-pressure sales tactics. Consider those that have positive consumer reviews on a trusted online site and are appropriately licensed, insured and bonded.