Expert Training

If CAD standards are as important as I claim, you might expect that indus-tries would’ve settled on a standardized way of doing things. No such luck. Although the manual drafting conventions in many professions have carried over to some degree into CAD, a lot of the things that need standardization have been left to the imagination of individual companies, departments, or people. For example, you’ll find that different companies usually name layers differently and employ different schemes for mapping object screen color to plotted lineweight (see Chapter 12). In particularly disorganized companies, you’ll find that different drafters use different layers and color-to-lineweight. And in the worst cases, the same drafter will do these things differently in different drawings!

As you can imagine, this proliferation of non-standard standards makes sharing and reusing parts of CAD drawings a lot more difficult. You can at least minimize the pain within your own office by conforming to any existing CAD standards or, if there aren’t any, by encouraging the development of some. (Later in this chapter, I give some suggestions for how to get started.)

Industry standards

Professional, trade, and governmental groups in some industries have made an attempt to promulgate CAD standards for the benefit of everyone in the industry. For example, the American Institute of Architects (AIA), together with several professional engineering associations, published a CAD Layer Guidelines document, which has become part of a so-called National CAD Standard that’s now promulgated by the U.S. government’s National Institute of Building Sciences, or NIBS (see www.nationalcad standard.org). The International Organiza-tion for Standardization, or ISO (the acronym reflects the French ordering of the words), publishes ISO standards document 13567 (see www.iso.ch). This document, which comes in no fewer than three parts, attempts to pro-vide a framework for CAD layer standards in the building design industries throughout the world.

These documents may be useful to you in your search for standards, but they aren’t a panacea. The majority of CAD-using companies has ignored officially promulgated CAD standards, because these companies developed their own standards and practices years ago and are loath to change. That doesn’t mean that you can’t use the officially promulgated standards, but they won’t suddenly make you a part of some mythical CAD standards mainstream. Practical implementation of most official CAD standards in a specific company requires a generous amount of clarification, modification, and additional documentation. In other words, you don’t just buy the document and then get to work; someone needs to tailor it to your company and projects. Some of these officially promulgated CAD standards documents are shock- ingly expensive. Apparently these organizations haven’t learned that the way to make something popular is to post it on the Web for free!

Even if you’re lucky or perseverant enough to get a well-rounded set of CAD standards in your office, that may not be the end of it. CAD-savvy people from different companies who collaborate on projects often want to minimize the pain of inconsistency during drawing exchange. Although each company may have its own CAD standards house in order, there’s no way that all of those standards will be the same. Thus, one or more companies (often the lead consultant) may impose a set of project-specific CAD standards. Project-specific standards don’t necessarily need to be as detailed as a full-blown company CAD standards document, but depending on the project and the person who created the project-specific CAD standards, they might be.

The result of confusing muddle of industry practices, company CAD standards, and project-specific CAD standards is that you find yourself switching among different standards as you work on different projects. Before you start making drawings, find out whether any particular CAD standards apply. It’s a lot easier to start off conforming with those standards than to fix nonconforming drawings later.