The floor plan symbols for doors and windows vary depending on the type of window or door that is being represented in the floor plans. Standard windows are usually identifiable as rectangular projections that are offset to the outside of an exterior wall. Casement window symbols look like a rectangle with two pieces of pie side by side projecting out of the rectangle. Exterior doors appear as rectangular shapes with a single pie shaped piece extending from it. Interior doors look the same, except that the line depicting the wall is broken at the doorway and is solid for exterior doors. Bi-fold doors are shown as dotted lines across an opening in a wall.