grossing factor
n.— «Coleman said the numbers take into consideration what is known as the grossing factor, that amount of space other than classrooms, such as corridors and bathrooms. Most everyone agrees that the existing building lacks in this department, so for planning purposes, the grossing factor has been bumped up from 1.42 percent to 1.58 percent.» —“District officials hear residents’ concerns about high school” Ambler Gazette (Fort Washington, Pennsylvania) Nov. 20, 2006. (source: Double-Tongued Dictionary)