Home and Garden

The windows in your home perform a host of functions. Keeping out inclement weather is critical, as is providing an abundance of natural light. But windows are also essential for regulating temperature in your home.

The right materials and the right construction can help keep energy costs low and keep you comfortable inside. Even the most expensive windows, however, aren't indestructible, meaning you'll eventually need replacements.

New window installation can be a costly process, so here's what you need to know as a homeowner.

A pane-ful reality: signs you need new windows

Broken glass or damaged window frames are sure signs that you need replacement.

Don't rely on these obvious markers, however, since they're only part of the story. If you suspect there's a problem with your windows, start by closing one and then standing nearby. Run your hand along the outside edge of the frame to check for any hot or cold spots. If you find any areas with a significant temperature difference, chances are the window isn't properly sealed. In some cases, it's possible to fix the frame and solve this problem but if the window pane has shifted or cracked, you'll need a new one.

You should also check for frost or water on the inside of your windows. If they are improperly insulated, the transition from hot to cold air may happen too quickly, resulting in moisture.

Sound is a good indicator as well. If you're noticing more noise inside your home or reoccurring air drafts, you may have poor-quality glass or (in older homes) single-pane windows.

In addition, make sure to check the outside of your home around the window frames. Peeling paint around the edges may indicate moisture traveling through the windows and causing exterior damage.

What it really costs for replacement

How much you'll pay for replacement depends on three factors: which window contractor you hire, how many windows you need and what type you want. Most of the time, the term "replacement" is a bit of a misnomer. Unless your home has significant water damage, frames stay in place while new glass panes and moving parts are installed.

The costs of new windows for your whole house can easily push north of $10,000. It's possible to lower this price by hiring a jack-of-all trades handyman but will take more time than if you hire a professional window company, since these pros typically bring an entire crew along to tackle the job.

You also need to be prepared for significant cost differences depending on what kind of windows you want. Awning and casement windows, for example, are relatively easy to install and come with a simple set of moving parts that allow them to swing open slightly. Double-hung windows, meanwhile, require more precise installation in order to open and close smoothly, whereas bay windows need proper support (typically cantilevered from below) to ensure they last.

The more time and effort installation takes, the more you'll pay. In addition, the number of glass panes in windows affects cost.

Most homeowners are familiar with double-pane windows, which have an air gap between the two glass panes to reduce heat transmission. You can also choose three or four-pane windows. The extra gaps are more effective at reducing heat loss, and some have gaps filled with argon gas to provide an improved thermal barrier. Expect to pay more — a lot more — for these types of windows.

Watch out for sticky prices

While it's impossible for window contractors to predict exactly what they'll find behind your walls, they should be able to walk you through the process of removal, any necessary repair and installation.

This means you should never trust an over-the-phone estimate: Always have your contractor come in person to your home. Make sure you do some research before that person arrives, and then ask about what type of windows he or she recommends. If the contractor insists on three- or four-pane windows to slow heat loss but won't acknowledge some of their drawbacks (e.g., higher weight, less visible light transfer) you may want to hire someone else.

And before you sign on with any contractor, get at least detailed estimates. Three is the rule of thumb for most residential construction work, but windows are critical. Not only do they significantly affect temperature levels in your home, but can offer great resale value if they're properly installed.