I don't see an issue with 6" foundation walls, as long as it is properly designed based on height of the wall and earth conditions. As some have said, many older homes have have been constructed with worse conditions (i.e. unreinforced concrete, brick, or rubble stone walls) and are still...
Common residential practice is to design the wall for an unsupported storey height between floors/roof (i.e. 8' for the basement wall and 8'-4" / 15' for the above grade walls). Detail your ledger board to be anchored to the wall, either using the Simpson hangers or anchor bolts. Where the...
