What type of wiring method is allowed for exposed locations in residential buildings?

Non-metallic sheathed cable (NM cable) is commonly used in residential wiring applications, particularly in exposed locations. This type of cable is preferable because it is flexible, lightweight, and easier to install than other types of wiring. NM cable consists of two or more insulated conductors and a bare ground wire, all housed within a non-metallic jacket, which makes it suitable for dry indoor locations.

When exposed to view in residential settings, NM cable is often permitted under the National Electrical Code (NEC) as long as it is properly secured and protected from physical damage. Its design allows for a more straightforward installation process in walls, ceilings, and other areas, meeting both code requirements and practical needs for residential construction.

In contrast, other wiring methods like metal conduit and rigid metal conduit are typically more suited for environments requiring additional protection against physical damage, moisture, or corrosive elements. These conduits involve more complex installation procedures and are generally used in commercial or industrial locations rather than typical residential settings. Underground feeder cable is also designed for underground use and may not be suitable or practical for exposed indoor applications. Thus, NM cable stands out as the most appropriate and commonly used wiring option for exposed locations in homes.