Having options is a good thing and until not that long ago there were few CAD or BIM options for Mac using Architects. Recently two new, traditionally Windows based programs, have been released with support for the Mac.
DeltaCad is a basic, easy to learn CAD program that can produce accurately scaled architectural or mechanical drawings. You can edit, scale, move, rotate, copy, etc. individual objects and it allows you to zoom in to draw fine details or zoom out to see the whole drawing. Learn more at DeltaCAD.
The other new Mac entry is BricsCAD. BricsCAD V15 for OS X offers 3D direct modeling with advanced 2D design. The new version offers cross-platform licensing, a familiar user interface, 3D direct and parametric modeling, Building Information Modeling (BIM), and 3D data exchange. All stored in standard .dwg files. Read a through review of Bricsys new BricsCAD for Mac over at Architosh.