Originally Posted by
Carbonfiberboy
A bubble level is monster accurate. 1° over 3' is a little over 1/2". If your house or place of business is that far out, you have some serious issues. My workshop was built in the late 40's and sits on concrete blocks. Its floor is pretty much dead on as shown with a 3' bubble level and thus out maybe 1/32" over 3'. I don't get the problem.
Out of curiosity I just measured saddle setback on 3 different hard floors around the house using a plumb bob. They are all within +/- 1 mm measuring with a steel rule. I checked the floor level with a metre long beam and digital inclinometer. All 3 floors were level within 0.1 deg.
While I agree you have to be careful, I don't believe it is THAT difficult to measure with reasonable accuracy.