Once upon a time, choosing a light bulb was simply a matter of deciding on wattage. Today, however, light bulbs come in a much wider range of options, with differences that are both subtle and not so subtle and can make a huge impact on your design and budget.

The old standby, traditional incandescent bulbs come in both cool and warm tones. They work by igniting a tungsten filament surrounded by an inert gas such as argon that conducts heat and prevents the filament from burning out immediately. Although this is still the most widely used type of bulb, it is also the least energy efficient and has the shortest lifespan, which is why it is gradually being phased out in favor of compact fluorescent lamp (CFL) bulbs. CFL bulbs put out the same basic type of light as incandescents, but their heat and energy output is much less, making them a desirable alternative for ordinary lighting.

For a brighter light, such as you might want in the kitchen or bathroom, halogen bulbs are a popular choice. Halogen bulbs work much like incandescents, except that the inert argon gas is mixed with halogen to extend the life of the filament. This also allows the filament to burn hotter and brighter than regular incandescents, which means a brighter light is obtained at a lower wattage, making them 10 to 20 percent more efficient than incandescents. They cast a warm light and can be used with dimmer switches, which makes them great for mood lighting. They require careful handling, though, and require glass coverings which can make them hot enough to raise a room's temperature and create a potential fire hazard if placed too close to flammable objects.

Xenon bulbs are becoming a popular alternative to halogen lighting. These bulbs use xenon gas instead of argon, allowing them to burn very brightly at cooler temperatures than a halogen bulb. They cast a cool, white light and don't require the special handling that halogens do, nor do they need a glass covering, which reduces their heat even further. Xenon bulbs generally cost more, though the extra cost is offset by their longer lifespan and increased energy efficiency.

In developing a lighting plan, decide which factors matter most: mood, brightness, cost-effectiveness or energy efficiency? The answer to this question will help determine which type of bulb is best suited to your lighting needs.