OVERVIEW

CHAPTER SUMMARY

This chapter describes approaches to implementing a layer-naming scheme for your CAD drawings. The chapter includes descriptions of several industry standards:

• AIA CAD Layer Guidelines

• CSI MasterFormat

• CSI UniFormat

• U.S. Coast Guard

• CalTrans Drawing Levels

• ISO Layers

All CAD packages give you the freedom to create many layers in the drawing. This leaves the new CAD user in a quandary: What do I do with layers?

Even though color is the subject of the next chapter, layers and colors are so closely intertwined that you'll notice the occasional reference to color in this chapter.

WHAT ARE LAYERS?

If you are familiar with overlay drafting, then it is easier to understand layers in CAD. Overlay drafting lets you combine several Mylar drawings to create a master blueprint. For example, to produce blueprints for the plumbing contractor, you combine the Mylar sheets of the site plan, the structural plan, and the plumbing plan. The plumber is not interested in seeing the furniture placement or the landscaping plan.

In CAD, layers let you have all elements of a project in a single drawing: site, structural, plumbing, furniture, and landscaping. You place each on a separate layer and then turn layers on and off to create plotted drawings as required. Turn off the furniture and landscaping layers to plot the drawing for the plumbing crew.