Another one from the bag of tricks is a simple stretchable detail item to represent rooms during space planning. Much like a sheet of trace paper to lay over your floor plan, this detail item affects none of the model elements allowing for very quick exploration of a few schematic options without the use of design options. Since this is a detail item, it's only visible in the view the work is done.
Two families have been created; one rectangular, the other L-shaped. A few types have been set up to show different wall thicknesses. A simple tag shows labels for the room name (optional), width & length (finish to finish), and resulting area.
By using reference planes and reference lines, the families will snap to each other, making it easy to align them. A center line for the wall thickness was added for reference.
All the families can be downloaded from here (2013).