Chapter 13 Visual Communication: Drawings, Renderings, and Models 463 Copyright Goodheart-Willcox Co., Inc. information. Abbreviations, graphic symbols, keys, and legends convey important information. Dimensions are another convention that ensures exact communication about sizes and placement of objects. Abbreviations Construction drawings often use abbreviations—shorter forms of words and phrases that replace the whole forms. They can vary among different trades. As you learn to read a set of construction drawings, look for standard abbre- viations. If they are not familiar to you, ask about them. You often find a list of abbreviations used in the construc- tion drawings in the first few pages of the document. See Figure 13-35 for some common abbreviations. Symbols Symbols are a type of pictorial shorthand language that reduces drawing time and coordinates separate draw- ings. Just as every page of the construction drawings has a title block, other pages that illustrate symbols include a legend—a combination of graphic symbols and notes— to indicate what the symbols represent. There are many types of legends in a set of drawings such as lighting, electrical, construction materials, and furniture plans. For example, a reflected ceiling plan uses lighting symbols and a demolition plan uses symbols indicating what is to be demolished as well as the placement of new construc- tion. Legends should be concise and readable. Symbols are divided into several types: material, line, and graphic. Material symbols represent types of construction materials. Line symbols relate to line weights and line types. Graphic symbols help index part of one drawing to another part on a different draw- ing sheet. Designers use common symbols that are universal throughout the industry. For example, standard doors are drawn open at 90 degrees to the wall, with arc of door swing indicated. Likewise, universal symbols outline door frames, wall systems, and windowsills. Symbols may also show window frames and sheets of glass. Symbols for stairs generally show four or five steps with a cut-off—a broken, angled line. The symbols “UP” or “DN” are adja- cent to stairs with a directional arrow. See Figure 13-36. Dimensions Dimensions are important on any construction drawing. They indicate the plan’s length, width, and components, as well as the distance of those components from each other. Dimensions include dimension lines with terminators such as arrows (or tick marks) that indicate where the dimen- sion begins and ends. They must be accurate, complete, easily readable, and following certain standards. Designers group and order dimensions in a hierarchi- cal manner. There are two standards for dimensioning a floor plan: The American Institute of Architects (AIA) and the National Kitchen and Bath Association (NKBA). ■ The AIA standard for general design drawings of floor plans uses the 1/4" = 1'-0" or 1/8" = 1'-0" scale. ■ The NKBA standard dimensions for specialized millwork drawings, which the designer draws to a larger scale, is typically 1/2" = 1'-0". Common Abbreviations for Construction Drawings A/C air conditioning AFF above finished floor Bldg building Bsmt basement Cab cabinet Cem cement Clg ceiling Clo closet Col column Conc concrete Ctr center Dia diameter Dim dimension Dn down DW dishwasher Elec electrical Elev elevator Ext exterior Gyp gypsum Hvac heating, ventilation, and air conditioning Incl include Int interior Kit kitchen Laund laundry Mech mechanical Mfr manufacturer Min minimum Nts not to scale Spec specification Std standard Typ typical Util utility Wc water closet (toilet) w/d washer/dryer Figure 13-35 Using common abbreviations consistently in construction drawings helps all team members understand the design plans.