A base map is a scaled plan drawing that documents the location of all the existing physical site elements such as driveways, walkways, patios, decks, terraces, walls, fences, steps, utilities, plant materials, and other visible elements (Figure 6—12). The landscape designer prepares the base map after all the necessary dimensions have been obtained from on-site measuring and other sources.
A base map is useful for two reasons. First, it records the existing site conditions before new design and construction. It can also help establish what specific elements need to be removed, replaced, replanted, or relocated later when actual construction begins. Second, the base map is used for the site inventory and analysis as discussed in Chapter 7. Both the base map and the site analysis are necessary in discussing the restrictions and potentials of a site with the clients. The designer will have difficulty relating new ideas to the reality of existing site conditions without an accurate recording of all existing physical site data.
A base sheet is a plan drawing that shows only those existing site elements that are to remain and be incorporated into the proposed design (Figure 6—13). This is a more simplified plan drawing in comparison to the base map. Site elements that will be altered or removed are not shown on a base sheet in order to give the designer a “blank slate” for maximum flexibility and creativity.