Decoding Plans I: Electrical Symbols

Pencil Points (January 1924) published its "Standard Symbols for Wiring Plans" that were recommended and adopted by the American Institute of Architects (A.I.A.), the Association of Electragists (A.E.I.), and the American Institute of Electrical Engineering (A.I.E.E.) Standards Committee on 6 March 1924. For those interested in decoding the symbology of early twentieth-century plans, this may help. As new units and circuitry developed throughout the late twenties and early thirties, professional architects recommended new symbols. These included designations for early HVAC (Heating, Ventilation and Air Conditioning) systems and radio aerial outlets. American Architect developed these tentative symbols as part of its Time-Saver Standards (December 1935).