Computers are great tools for architects, but don't let CAD go wild

Architects can now design buildings without lifting a pencil, thanks to computer technology. In fact, digitally conceived architecture can be too complex to draw by hand or to develop using conventional drawings, even those printed by machine. Yet there may be risks in abandoning the pencil and relying so completely on the computer.

Drawing manually used to be an indispensable architectural skill, and not just for mechanical drafting. Drawing by hand was how historic architecture was documented and analyzed, and how incipient design ideas were recorded and explored graphically. For many architects, drawing by hand is both inherently pleasurable and integral to critical design thinking, a way to directly and creatively connect the eye, brain and hand. But today, computers enable architects to do little or no manual drawing, and drawing less by hand may tempt some architects to think less critically.

In architecture offices today, you rarely find a drafting board with a parallel bar, rolls of tracing paper, measuring scales, triangles, drawing templates or boxes of pencils and markers. Instead you see a workstation with a flat-screen monitor, keyboard and mouse. Many designers use computers for "drawing" everything: diagrams, preliminary design studies, three-dimensional views and construction documents. Produced on large-format printers, drawings can even be made to look like hand-drawn sketches.

Computer-aided-design (CAD) has transformed architectural design methodology, not because it eliminates manual drawing, but because it allows architects to compose stacks of drawings at every stage of design. Architects can show clients countless design variations, create realistic renderings and graphic simulations, and produce detailed construction documents.

Once preliminary design studies - site plan and massing studies, floor plan layouts, sections and elevations - are undertaken and a preliminary digital model is created, the architect can obtain three-dimensional views, including animated walk-throughs or fly-throughs. The designer also can modify any part of the project, whether a house or a high-rise, and CAD software can automatically edit and update all parts of the design affected by the modification.

CAD software can manage a vast amount of layered data, keeping track of and coordinating all digital model components and systems, such as the structural skeleton, windows, doors, interior partitions, floor finishes, ductwork and plumbing. These programs can alert the designer if components conflict geometrically and can instantly recompute dimensions, floor areas and material quantities.

It gets even better. When a design is finalized and fully defined in a three-dimensional digital model, CAD programs can print annotated, two-dimensional drawings for bidding, building permits and construction. For highly complex designs that cannot be adequately represented and interpreted using conventional documents, the digital model itself can become the primary documentation.