Stephens lowered the amount of energy consumption by replacing (one for one, where possible) the inefficient High Intensity Discharge (HID) lighting in exterior walkways at buildings 4640, 4650, and 4664 with more energy efficient compact fluorescent fixtures while maintaining as close as possible the average maintained illumination level that was currently existing at the buildings. Stephens also replaced the incandescent fixtures within the day rooms at the same buildings with more energy efficient compact fluorescent fixtures while maintaining the same average maintained illumination levels.