Whenever I open a new drawing and go to the Terrain menu or try and select any of the Terrain tools on the toolbar, they are grayed out and inaccessible.
Why is this?
Before you can use the various Terrain tools, you must first create a terrain perimeter, and the floor the terrain perimeter was created on must be the active floor. The terrain perimeter provides Chief Architect with an area for terrain objects to be placed within.
The terrain perimeter is a closed polyline defining the boundary of the terrain that generates in 3D views and displays contour lines that are generated in plan view.
from the menu to create a basic rectangular terrain perimeter, then select Window> Fill Window 
to see the terrain perimeter's extents.
or by accessing the Active Layer Display Options 
side window. 
, access the Line Style panel to see the exact layer the terrain perimeter is on, then enable the display of this particular layer. To learn more about layers, please see the Related Articles section below.
to try and locate the perimeter. By default, the perimeter is a 50' x 100' rectangle and looks like the following image. 
, change the Delete Scope to All Floors, place a check in the Terrain Objects checkbox, then click the Delete button. Only proceed with this option if you're sure you want to delete the terrain perimeter and all existing terrain objects from the design.
