Plan views can be thought of as a map of a particular level of the structure with the orientation of the view looking downward from above. In structural engineering, a plan view for a floor uses a view range to isolate a specific floor. The view range typically begins at 4 feet above the level and ends at 4 feet below the level. Everything which is cut at the typical 4 feet above the level is displayed in hatching. Pictured is the CMU hatching (Figure 2, item 2). Everything which is seen at the surface is shown in solid lines (item 1). All elements which are beneath other elements, such as beams, are displayed with hidden lines (item 3). Technically, a plan view is defined as a vertical orthographic projection of an object on a horizontal plane. An example plan view is shown in figure 3.
For structural engineering, in practical terms, this results in a few common types of plans: foundation, framing, and roof plans. The foundation plan, which is typically the first plan that is shown in the set of structural documents, shows foundation building geometry including but not limited to; grade beams, piers, footings, and the relationship of these items to the building grids. The framing plan shows the horizontal structural elements at a given floor or level along with their relationship to the building grids. Finally, the roof plan shows the upper structure of the building and will typically indicate roof framing, including roof access openings and mechanical HVAC equipment on the roof.