Good drawing skills are not something that can be learned in architecture schools. Although existing abilities can always be improved, drawing is usually an innate talent that a person is born with.
The specialized type of drawing that architects use in their work, which is included in architecture school curricula, is known as drafting. Drafting uses standardized symbols, lines, layouts, descriptive geometry, dimensions, view projections, text sizes, and notation to create technical drawings that render ideas into physical form and can be interpreted the same way by all architects.
There are three main methods of drafting: sketching, manual or instrumental, and computer-aided design (CAD):
Sketching is a cursory freehand drawing that is not meant to be used for a finished product but is intended to preserve an idea for future use. Architectural sketches are actually more like diagrams, in which geometric symbols represent certain kinds of information. Architects use sketches to test ideas and communicate those ideas in a visual form to clients or design engineers.
Manual or instrumental drafting involves the use of paper, a drawing board or drafting table, and a sliding straightedge instrument called a T-square, which is used as a guide for drawing horizontal, vertical, or diagonal lines. Other tools such as compasses, French curves, and splines can be used to help draw circles and curves. Because these tools must be positioned correctly to produce accurate drafts, modern drafting tables are equipped with a mechanical drafting machine that slides freely across the drawing board. This tool allows the drafter to create an accurate right angle anywhere on the drawing.
Computer-Aided Design (CAD) is an electronic version of a drawing board and has mostly replaced drafting tables. CAD software can come in two-dimensional (2D) or three-dimensional (3D) systems. Two-dimensional CAD software creates lines, circles, arcs, and curves, while 3D CAD creates views of the objects from different angles and allows individual parts to be put together to represent the finished object. The two systems are often used together, with 2D creating drawings that allow the structure to be built and 3D visualizing what the finished structure will eventually look like. Even with CAD, there is still room for error, and the natural technical skill of the drawer is still needed to produce accurate drafts.
Drafting involves a basic underlying knowledge of geometry, trigonometry, and spatial comprehension, as well as attention to detail.