Expert Training

Blocks and xrefs are useful for organizing sets of drawings to use and update repeated elements . It’s not always clear, though, when to use blocks and when to use xrefs. Applications for xrefs include

• The parts of a title block that are the same on all sheets in a project.

• Reference elements that need to appear in multiple drawings (for example, wall outlines, site topography, column grids).

• Assemblies that are repeated in one or more drawings, especially if the assemblies are likely to change together (for example, repeated framing assemblies, bathroom layouts, modular furniture layouts).

• Pasting up several drawings (for example, details or a couple of plans) onto one plot sheet.

• Temporarily attaching a background drawing for reference or tracing.

On the other hand, blocks remain useful in simpler circumstances. Situations in which you might stick with a block are:

• Components that aren’t likely to change.

• Small components.

• A simple assembly that’s used repeatedly, but in only one drawing. (You can easily update a block in one drawing with the REDEFIT command.)

• When you want to include attributes (variable text fields) that you can fill in each time you insert a block. Blocks let you include attribute definitions; xrefs don’t.

Everyone in a company or workgroup should be consistent about when and how to use blocks and xrefs. Check whether guidelines exist for using blocks and xrefs in your office. If so, follow them; if not, it would be a good idea to develop some guidelines. Chapter 14 discusses how to start such guidelines.