Another barn question. I have a two-story city barn with a sagging wall,
and I would like to first determine the amount of sag, the amount of
tilt, and any other out-of-square, out-of-level conditions, before
proceeding with any remediation. Ultimately this may include replacement
of corner posts, sill plates, and repair of a foundation. I'd like to do
as much of this work myself as possible.

From reviews such as Amazon, I find that the consumer-priced laser
levels are said useful mainly for things like shelving, as they project
a line on a flat surface.

I would like to use a laser level for this job, but would it help? Would
I have to buy a pro tool that costs hundreds of dollars to be of use? Am
I stuck using squares, bubble levels, plumb bobs, chalk lines, and other
tools?