A -- Old leaky windows not only drive up your utility bills, but they make you feel uncomfortably cold (and hot in the summer), allow dust/allergens indoors, sweat during cold weather, and allow furniture and carpeting to fade. Also, when you install good-quality replacement windows, the first thing you will notice is reduced road noise near a window.
Wood frames are still very popular for new and replacement windows, even though they may require some maintenance, because no other frame materials match their beauty. Many windows, with natural-wood interior surfaces and vinyl- and aluminum-clad wood exteriors, are virtually maintenance-free.
The year-round utility bill savings from installing new replacement windows result primarily from the new, more efficient types of glass and airtight weatherstripping. Since the window frame itself makes up a relatively small percentage of the total window opening, its design and manufacturing quality are more important than its material type.
The wood frame material is a natural insulator and never feels cold to the touch. With the many new types of low-emissivity thermal glass available, with up to four panes and/or films, window condensation will be very rare and you won't get that chilly feeling when sitting near a window at night.
Whether or not installing replacement windows will provide a good economic payback is a difficult question to answer. Ask lots of questions and be wary of claims that sound too good to be true.
The actual dollar payback from lower utility bills depends on many factors: efficiency of your heating and air-conditioning system, number and orientation (to the sun) of the windows, condition of your existing windows, etc. Ask several window contractors to do computerized savings payback analyses for you. Keep in mind that the other non-economic, convenience advantages of installing new windows are also important.
Wood window frames provide a virtually endless array of styles, shapes, and sizes. It is much less expensive for the manufacturers to make the tooling to machine wood for various frame contours than it is for aluminum or fiberglass. This makes them ideal for older houses where you may want to match the existing windows. If you prefer the natural look of a clear finish, windows made of mahogany, teak, cherry, redwood, and ash are available.
Almost all the wood window manufacturers offer the standard styles of single- and double-hung, casements, awning, hopper, etc. For the greatest overall efficiency, choose casement windows that close on the weatherstripping with a compression fit. This provides a long-term airtight seal.
More domestic companies now offer tilt-turn windows that have been popular in Europe for years. This window design provides the airtight compression-sealing benefits of casement windows, as well as security against unwanted guests when the window is opened for ventilation.
Once you have selected the style of window that you desire, you must select the type of glass. The best type of glass to select will depend on your climate and whether winter heating or summer air-conditioning bills are your primary concern. In most cases, some type of thermal-pane glass with a low-emissivity coating or film in between the panes would be the minimum quality to accept.

Write for Utility Bills Update No. 719 for a buyer's guide to wood windows. Include $3.00, a business-size SASE, and Update number. Mail requests and questions to James Dulley, Kentucky Living, P. O. Box 54987, Cincinnati, OH 45254. Go to www.dulley.com to instantly download.