I've been thinking about adding in a retaining wall feature that auto sizes the rebar and qty. based on my typical retaining wall details:
For stemwall foundations I typically check the footing width (bearing pressure) and min. rebar for shrink (ACI 318-11), see engineering calcs per this PDF:http://design.medeek.com/resources/footing/STEMWALL_FOOTING_CALCULATOR.pdf
I could easily incorporate this type of engineering calculations into the plugin, however I'm still trying to figure out how to have the plugin output PDF reports, or Excel spreadsheets, which would be necessary if engineering reports become part of this plugin.
Same sort of thing with square or rectangular footings can be done:http://design.medeek.com/resources/footing/SQUAREFOOTING_CALCULATOR.pdf
With stemwalls or pony walls (not necessarily retaining walls) that exceed 24" in height (but not in excess of 48") I like to add #4 bars cont. horizontal at 18" o/c. Logic could be incorporated that adds in additional stemwall and foundation wall rebar per a number of prescriptive criteria, IRC tables etc...
Currently it is entirely up to the users to specify rebar size and qty. with both stemwall and slab on grade foundations.
Stemwall foundations allow you to place rebar at the top of the wall (5" below top, qty. 1,2, or 3 bars) and rebar at the bottom of the wall (3" above bottom, qty, 1,2, or 3 bars). It also allows placement of bar in perimeter footing and interior footings (qty 1,2 or 3 bars). Bar sizes range from #3 to #8 and similar sized metric equivalents for the metric templates, I can always add more sizes if requested.