Low-voltage outdoor lights are inexpensive and easy to install. Kits typically include five or more lights, cable, and a transformer/timer. Some lights are mounted on stakes poked into the ground; others can attach to posts. The cable runs in a shallow trench or sits on top of the ground, covered with mulch; the transformer/timer simply plugs into a standard receptacle. Low-voltage lights are bright enough to light a path, accent foliage, or provide lighting for an outdoor dining area. More extensive illumination or installing an outdoor receptacle requires extending household 120-volt wiring outside.
Choosing lights and switches
The first step in an outdoor wiring project is to decide where to place lights and receptacles. Gather more tips by consulting with neighbors and salespeople. For switches there are four basic options: standard, timers, motion sensors, and photocells, which turn lights on at dusk and off at dawn. Motion sensors and photocells often are built into outdoor light fixtures such as floodlights, but you can also install them as separate devices that control several lights.
If you already have an outdoor receptacle and if its circuit isn't overloaded when you add new service, tap power from it. If this is not possible you can move power outdoors by running lines and installing fixtures.
A building permit is required for running line-voltage cable outside. Local codes vary considerably, so have your building department approve your plans before you start work. Be clear on what sort of cable and/or conduit is required, how deeply underground it must be buried, and what type of weathertight connections and fixtures are required. Contact utilities to locate underground cables and pipes before you start digging.