In the following exercise, you'll use some pre-drawn lines to help you begin laying out exterior and interior walls. This does not mean that you'll always need or have such lines to begin using Revit. We do it here so you can move through the exercise efficiently and to avoid burdening you with typing in every dimension value. In real life, there are many different ways to start a project from an existing 2D import (covered in Chapter 7), from a conceptual massing form, from an imported image, or from scratch. As you will see, Revit has many useful features when laying out walls, especially the smart temporary dimensions that let you see and edit dimensions of elements before and during creation.

In the exercise, we will start with a set of lines, and construct 3D walls using these lines as guides. In fact, the lines are named guides, and are located in the Line Styles dialog box, if you feel the need to edit their appearance. To follow along with the process of building exterior and interior walls throughout the rest of this chapter, open the exercise base file named Source_House_Walls_Start.rvt at the book's companion web page, www.wiley.com/go/introducingrevit2009. The model opens with the Level 1 plan view active. Several levels are predefined for first and second floors as well as for some roof planes.