Window Buying Guide
Finding energy-efficient windows has become easier, as insulating features such as heat-reflecting low-E coatings and argon
gas between panes have become more standard. You'll also find new options and extras, including fiberglass window frames.
Use this buying guide to make your selection.
- Getting started
- Types
- Features
- Brands
Features
The traditional single sheet of clear glass offers little insulation against frigid winters and frying summers. With energy conservation a major issue these days, the market
Double or triple glazing
Double-glazed windows have a sealed space between the two panes of glass, and the air in the space provides an added layer of insulation. Compared with a single pane, double glazing can cut heat loss nearly in half. The insulating value of triple-glazed windows is higher still, but the extra layer adds to weight and cost.
Low-E coating
Clear glass allows large amounts of radiant energy to pass through--heat in from the sun in summer, heat out from your house in winter. A low-E, or low emissivity, coating is a microscopically thin metallic film that acts something like a two-way mirror, reflecting heat back into the house in winter and blocking heat from the sun in summer. Which it does better depends on how the coating is applied. The windows can be fine-tuned for different climates, producing Southern or Northern windows, for example. Some coatings may darken the glass, like tinted glass in a car, an effect some people might not like. Check a sample at the store.Gas filled
Instead of air in the sealed space between glass panes, these windows use argon, krypton, or other inert gas. These gases are denser than air, so they provide better insulation.Cladding
This is the vinyl or aluminum that covers the exterior of a wood window so that it doesn't have to be painted.Tilt-in sashes
On windows with this feature, the sash (moving part of a window) can be tilted for easy cleaning.
