If you’ve ever shopped for replacement windows, you know that it can be one of the most confusing and frustrating quests you’ve ever engaged in. There are many different options—vinyl, aluminum, wood, fiberglass. And what’s the best system—sash only? Sash in a unitary frame? A whole new window? Complicating the issue is that the replacement window business is famous for high-pressure sales tactics, bait-and-switch marketing tactics, widely varying prices and more than its share of questionable customer service.

 

Here’s what you’ll need to make good decisions about the replacement windows that are right for you (also see “The Do’s and Don’ts of Replacement Window Shopping"):

 

 

Most people consider replacement windows because:  A) Their existing windows don’t operate easily; B) The existing windows are damaged and unsightly; and C) They want more energy-efficient windows for greater comfort and lower energy bills.

 

The good news that virtually any type of replacement window one selects is likely to operate more easily, look better and offer greater energy-efficiency than existing windows if they have insulating glass (double or triple panes) and are installed properly.

 

 

Three different systems can be called replacement windows: A) Sash replacements; B) Sash replacements in a unitary frame; and C) Prime windows—full window units with structural frames and sills such as those that would be used in new construction.

 

Sash replacement systems generally consist of insulating glass panels set in frames and whatever else may be needed to replace the movable parts of a window. Sash replacements are usually the simplest, least expensive alternative. They’re the best option if the existing window frame is sound (no rot) and visually acceptable. Installation requires no disturbance of existing window trim, siding or interior wall finishes.

 

Replacement sash in a unitary frame cost a bit more than sash-only replacements. Units are designed to be installed inside sound existing window frames. Installation requires little or no disturbance of existing window trims and siding. They’re a good option for cases in which an existing window opening is not perfectly square. Because of the way they’re constructed, replacement sash with unitary frames may reduce the size of the clear glass area from that of the window being replaced. Gaps between the new frame and the old one into which it’s been installed are usually concealed with aluminum capping on the exterior, which may be an aesthetic sticking point for some owners.

 

Replacement with prime windows is the most expensive option, needed when frames of existing windows show rot or other water damage, or to enlarge existing windows. Exterior and interior trim must be removed along with some siding to tear out the existing window. Wall framing may need replacement or alteration. The source of water damage and other structural issues that may have led to the need for window replacement should be identified and repaired before the new window goes in and the finishes are restored.

 

The materials choices for replacement windows are A) vinyl; B) aluminum; C) wood; D) clad wood and E) fiberglass. Each has its pros and cons.

 

 

When fairly priced, vinyl windows are by far the most affordable among all of the options. In addition to the attractive price tag, vinyl requires no painting and has appealing thermal properties. It doesn’t conduct heat or cold, which contributes to comfort and moderates energy costs.

 

Vinyl’s detractors, who include makers of other types of windows and architectural traditionalists cite these shortcomings:

 

Most vinyl window suppliers offer good-, better- and best-quality options at escalating price points. Higher-quality vinyl windows are engineered to overcome most of the material’s vulnerabilities. The strongest, most stable vinyl windows are made from the thickest plastic; high-quality extrusions — the stock from which the frames and sash are made — are divided into a number of cells, which you can see by looking inside the cut end of a sample. And in good-quality vinyl windows, corners and joints are heat-welded rather than assembled with metal corner brackets and screws.

 

 

Aluminum replacements are roughly comparable in cost with better-grade vinyl windows. Like vinyl, aluminum doesn’t decay and needs little or no maintenance, but unlike vinyl, it can be painted with much better results. Aluminum is stronger and more dimensionally stable than vinyl, but aluminum window frames do not insulate as well as either vinyl or wood. Aluminum windows are also more prone to condensation than other types.

 

 

Wood windows generally cost two to three times more than either vinyl or aluminum. Wood windows are structurally strong, dimensionally stable and offer energy performance comparable to vinyl. For durability and cosmetic appeal, wood windows require painting. Factory-applied exterior cladding of vinyl or aluminum adds something to the price of wood replacement windows but eliminates the need for painting.  Wood windows are widely preferred by traditionalists for their architectural details.

 

 

Fiberglass windows are comparable to wood windows in price and virtually every performance property except one — they never need painting. A variety of exterior and interior finishes can be applied at the factory, including natural-looking wood grains.