What rebar to put in standard residential foundation wall with a crawl space?

[MJC6125]

What do you all need for foundation wall reinforcement in a standard residential project with a wood framed first floor and crawl space underneath it like in the image below? Do you need to worry about designing this wall and footing like a basement wall for the lateral earth pressures? Or is it OK to just put some nominal amount of reinforcing. What do you typically put in terms of vertical and horizontal bars, and how far do you space your footing dowels?
Lastly, do you know if they typically excavate the crawl space down to the top of footing elevation like I have it shown or do they excavate just to about -18" below structure per code? Obviously this question is only important if you footing is lower for frost requirements.

 

[KootK]

I've been doing two bars top and bottom in the stem wall with those adding up to 0.18% of the stem. #4 verts @ 48" oc assuming that lateral loads can be handled with plain concrete strength. No real rationale other than a desire to be cheap, have things generally not fall apart, and have some capacity to span soil soft spots.

I like to debate structural engineering theory -- a lot. If I challenge you on something, know that I'm doing so because I respect your opinion enough to either change it or adopt it.

 

[WARose]

If I recall correctly, by the 2015 International Residnetial Code [IRC] the max. allowable soil differential after which you need to start thinking about doing a design (as per the design codes) is about 48" (where there is no lateral restraint for the wall at the top & bottom). If you have more than that (unbalanced by the load on the other side) that's where a engineered design comes in. In the IRC they have several prescriptive designs (assuming you are in the right seismic design category) that have wall footings without reinforcement.