Although there are no national or local electrical code requirements for the mounting height of switches, there are height requirements set down by the Americans With Disabilities Act for a dwelling that may be inhabited by people with physical challenges. The ADA specifies a maximum height for a side reach of 54 inches, and a maximum side down reach of 8 inches for people seated in wheelchairs. Although those standards were set for public buildings and health care facilities, they are a good standard to follow when constructing or remodeling a private residence.
Locating the Switches
Light switches controlling the bedroom's main lights are located on the wall opposite the hinged side of the entryway door. Measured from the finished floor line, the top of the switch box should be no more than 54 inches high. By convention, most switch boxes are installed with the bottom of the box located 44 to 46 inches above the floor, this places the top of the box between 47 1/2 and 49 1/2 inches above the floor. By using these conventions, the top of the box is below the maximum 54 inches set down by the ADA.
When remodeling large bedrooms, you may want to consider installing three-way switches instead of the standard single-pole switches, because the three-way switches allow you to control the light from two places in the room. By placing the second three-way switch near the bed, you are not left stumbling around in the dark when you retire for the night.
Mounting the Switches
If the switch boxes are being installed in a new bedroom addition, the boxes are mounted directly to the side of the king stud, the two-by-four that runs from the bottom plate to the top plate, the horizontal wall framing members. During a remodel where the walls already are finished, remodeling or "old work" boxes are used, which are held in place by mounting wings that swing out and press up against the backside of the wall.
Other Light Switches
For lights other than the bedroom's main luminaries, the switches are mounted in close proximity to the light fixtures they control, such as wall sconces mounted to either side of a bed's headboard. In this case, the switches should be mounted at a height easily within reach of a person reclining on the bed. In a case where the main room lights already are in place and controlled by a single-pole switch, you may want to consider using three-way switches to control the bedside wall sconces, so you can turn them on upon entering, then turn them off after you are in bed for the night.