I have a very old carriage barn on my property (built around 1856) that is in dire need of repair and restoriation. It's fairly small (16' x 20') and is leaning. The original sill sits on the ground (no foundation yet). My objective is to build a 6"x6" frame on the inside first floor of the barn, raise the barn to sit on the frame, let the barn settle and straighten, build a new foundation, and repair/replace the rotted wood of the original barn.

Is this the smartest way to go, and what's the best (and safest) way to jack the barn up without it collapsing around me?