Understand the location line setting on walls and how the wall is affected when layer thickness is changed.
This video demonstrates the following:
When you add walls to your model, you must specify the location line. The location line establishes where the geometry of the wall layers will be in relation to the line. This position is important if there is a chance the wall structure or wall type will change during the design process. If positioned incorrectly, geometry may shift and critical dimensions may change.
In the 2 examples, the set of walls on the left has the wall location line set to the interior finish face of the wall. The set of walls on the right has the wall location line set to the exterior finish face of the wall. The dimensions on each set of walls are dimensioning the overall footprint of the building.
When the structure of the wall is changed to use a CMU structural layer instead of a wood stud, the thickness of the core of the wall is changed to match the CMU dimensions. Because the sets of walls have different location lines, the additional thickness of the CMU was accommodated in a different way for each set of walls resulting in a change in the dimensions on the walls on the left.
To understand what is happening, notice the 3 walls drawn with their location lines aligned to each other. One wall is aligned to the finish face interior, one aligned to the finish face exterior, and one aligned with the location line positioned in the center of the wall. Dimensions have been added to illustrate the wall faces relationship to the location line.
When the wall structure is changed, you can see the wall location line remains in position and the faces of the wall are adjusted in relation to it. The wall location line will not change, the faces of the wall will change when the thickness of the wall structure is changed or the wall type is changed.
Wall location lines can be set to interior or exterior faces, the interior and exterior faces of core layer in the wall, or the mid-point of the wall or the wall core. Layout walls in your model using the location line at the critical dimension of the wall to insure your design intent is maintained if wall types are changed.