The last two story addition we did the plan checker told us we couldn't underpin the single story footing to get it to carry the weight of the 2nd story. This took us by surprise as it had never come up before. Since then California has gone over to the CRC which is basically the IRC and now we have a possible 2nd story addition and would prefer to underpin the footing, tying it together with rebar dowels, rather than removing the footing and replacing it with a larger one. I've been reading through the code book and don't see where this is prohibited but don't see where it's condoned either. I've attached a stripped down detail showing what we normally do and are planning on doing.TIA for all comments,Rio
View attachment 1525
Underpinning (1).pdf
Underpinning (1).pdf
View attachment 1525
Underpinning (1).pdf
Underpinning (1).pdf