I agree - with Ernie...it sounds also like you haven't done this before. We consult with engineers whenever necessary before attaching or changing anything structural. There are 3 huge benefits.
1)You will know if it is possible or not before you get yourself in too deep.
2)They might offer an easier faster cheaper solution that you might not have thought of.
3)Even though you are still liable...they share the liability by approving plans. This might be the most important.

and it'll help you sleep at night :)