In View mode, when you click on the any wall, the context bar displays an insert icon. When you click on this, it enables you to add an insertion point. (It displays the distance from either end to the insertion point} To add a new wall from this point go to the Draw Tool and draw from that point. The new wall has the same details as the existing wall....... Great question!
Click on the wall. Select the "Split Wall" option from the context bar and click where you would like to add an intersection. USe the draw tool to draw a wall segment from this newly created intersection.
Remember do not draw internal walls from the perimter walls ----
