Blueprints and Construction Drawings: A Universal Language 15
2.3 COMPUTER-AIDED DRAFTING (CAD) AND COMPUTER-AIDED DESIGN AND DRAFTING (CADD).
Moving from manual drafting to computer-aided design and drafting was an important step in terms of
the potential of today’s technology. CAD originally meant computer-aided drafting because of its origi-
nal use as a replacement for traditional drafting. Now it usually refers to computer-aided design to re-
flect the fact that modern CAD tools do more than just drafting (Figures 2.5A, B, and C). Related
acronyms are CADD, which stands for computer-aided design and drafting; CAID, for computer-aided
industrial design; and CAAD, for computer-aided architectural design. All of these terms are essentially
synonymous, but there are a few subtle differences in meaning and application. CAM (computer-aided
manufacturing) is also often used in a similar way or as a combination (CAD/CAM).
When we use computer-aided design and drafting (CADD), certain questions arise that we never
think of when working on the drawing board. Although with CAD or CADD we do not use the typical draw-
ing-board tools, we are still required to design or make a drawing.
CADD is an electronic tool that enables you to rapidly create accurate drawings with the use of a
computer. In fact, an experienced computer drafter can normally produce a construction drawing in less
time than it would take if it was done manually. Moreover, unlike the traditional methods of making draw-
ings on a drawing board, with CADD systems you can create professional drawings just by using a
mouse and clicking buttons on the keyboard. Furthermore, drawings created with CADD have many ad-
vantages over traditionally produced drawings. In addition to the fact that they are neat, accurate, and
highly presentable, they can be easily modified and converted to a variety of formats. In addition, CADD-
generated drawings can be saved on the computer, a flash, a CD, or an external hard drive in lieu of vel-
lum or Mylar sheets that require the use of large storage cabinets for filing.
A decade ago CADD was largely used for specific engineering applications that required high pre-
cision, and because of CADD’s high production costs, not many professionals could afford it. In recent
years, however, computer prices have dropped significantly, and professionals are increasingly taking
advantage of this by adopting CADD programs.
There is a wealth of CADD programs available on the market today. Some are intended for general
drawing work, while others are designed for specific engineering applications. There are programs that
enable you to do 2D drawings, 3D drawings, renderings, shadings, punch lists, space planning, struc-
tural design, piping layouts, HVAC, plant design, project management, and other applications. Today we
can find a CADD program for almost every engineering discipline that comes to mind.
CADD Presentations.
Although CADD is primarily intended for single-line drafting and has very limited capabilities to create
artistic impressions, CADD’s 3D and rendering features are quite impressive. A 3D model of an object
can be created and viewed from various angles and, with correct shading and rendering, can be made
to look very realistic. With CADD you can create fine drawings with hundreds of colors, line types, hatch
patterns, presentation symbols, text styles, and other features. Even if you don’t like something about
your presentation after you have finished it, you can instantly change it (Figure 2.6).
Most CADD programs have a number of ready-made presentation symbols and hatch patterns avail-
able that can be used to enhance the look of drawings. When drawing a site plan, for example, a
draftsperson can instantly add tree symbols, shrubs, pathways, human figures, and other landscape el-
ements to create a professional-looking site plan. Similarly, an architect can use ready-made symbols