However, designers and drafters continue to modify some of these symbols to suit their own particular needs for the types of projects they are normally commissioned to design. The majority of architects and engineers today use symbols adopted by the American Institute of Architects (AIA) and the American National Standards Institute (ANSI). Symbols may vary slightly from one locale to another. Visualizing and reading construction drawings therefore necessitate a knowledge of symbols and abbreviations used in the construction industry and of their proper use in representing materials and other components and their locations (Figure 8.2). Drawing simple building components without the use of symbols would indeed be a tiresome task. In the preparation of working drawings for the building-construction industry, architects and engineers have devised systems of abbreviations, symbols, and keynotes to simplify the work of those preparing the drawings and to keep the size and bulk of the construction documents to an acceptable, comprehensible minimum. For example, a circle drawn around an area of a drawing with an extension to a number would indicate that this portion of the drawing has been drawn to a larger scale to provide more information than would be possible at the existing scale (Figure 8.1). One of the main functions of graphic symbols on construction drawings is to reference other drawings within the set. Blueprint drawings-as applied to the building- construction industry-are generally used to show how a building, object, or system is to be constructed, implemented, modified, or repaired.

Electrical blueprint symbols