The term “sick building syndrome” is used so commonly these days that you might hear it just referred to as “SBS.” A building is considered to be “sick” when occupants experience acute health and comfort effects, most likely resulting from poor indoor air quality. The specific cause of these effects must be unknown, but the general discomfort is shared by multiple occupants of the building (a “building related illness,” or BRI, occurs when the illness is diagnosable and the cause can be attributed directly to airborne building contaminants).