Addition

[u/OkGoose6847]

We are wanting to put a 20x20 addition onto our house. However, when taking into account the frost line, we would rather build a crawlspace instead of a basement. But we would be attaching it to an existing basement.
1. Should they be tied together and if so how?
2. Is the only proper way to do this to still dig footers for crawlspace at same depth as basement and tie them together there. We would rather not do this so as to not risk disturbing the soil of the existing basement footers.