The verb "plan" denotes several things, two of which interest us here. One is making a map of a horizontal surface, such as the ground or the floor of a building; the other is deciding how things should go together. These two meanings come directly from two Latin words from which "plan" is derived: plantare, meaning to fix in place, and planum, meaning level ground. Architects tend to use "plan" in the specific sense of a floor map, while the average home owner tends to refer to the more general idea of a spatial description. In the vernacular, "drawing up the plans" includes everything necessary to document a house, including design, details, sections, elevations and specifications— the plan