in general, denotes the representation of something drawn on a plane; such are maps, charts, inchographies, &c. See Map, Chart, &c.

The term plan, however, is particularly used for a draught of a building, such as it appears, or is intended to appear, on the ground; shewing the extent, division, and distribution of its area, or ground-plot, into apartments, rooms, passages, &c.

A geometrical plan is that wherein the solid and vacant parts are represented in their natural proportions.

The raised plan of a building, is the same with what is otherwise called an elevation, or orthography. See Orthography.

A perspective plan, is that exhibited by degradations, or diminutions, according to the rules of perspective. See Perspective.

To render plans intelligible, it is usual to distinguish the masonry, with a black wash; the projections on the ground are drawn in full lines, and those supposed over them in dotted lines. The augmentations, or alterations to be made, are distinguished by a colour different from what is already built; and the tints of each plan make lighter, as the stories are raised.

In large buildings, it is usual to have three several plans, for the three first stories.