The wall is based on the wrong source

[Anonymous]

It is based on the middle of the wall:

But I wanted it to be based on the face, like this:

[barthbradley]

Are you talking about the Wall's Justification?  Or, are you referring to the Wall's Temporary Dimension Witness Line Location?  Or, are you talking about where the end points are of the two wall meeting at the intersection? 

I'm going to go with the last one.   You don't like where the end point are located.  Easy fix. Disable automatic joins of both walls meeting at the corner, line up wall ends manually the way you like, and use Join Geometry to remove the visible edges between them (optional).   Note: When you draws walls, you can disable Automatic Join from the Options Bar.  

[Avaris.]

In case you are referring to the temporary dimensions:

Click Manage tab > Settings panel > Additional Settings drop-down > Temporary Dimensions

[ennujozlagam]

if you are referring the location line of the wall? just click your wall > go to properties > and select your location line. thanks