Most carpenters frame and trim whole houses with
nothing more than a 4- or 6-foot spirit level to find
plumb and level. But a level is a poor tool for plumbing
tall walls and columns, for laying out long horizontal runs of
trim, and for aligning window heads. Mistakes made while
framing walls resurface later when you frame the roof; sloppy
installation of windows and doors fouls up the alignment of
frieze boards and clapboard courses; and small leveling errors
accumulate into major installation problems with interior trim
and cabinets.
In each of these cases, a transit is much more accurate.
While it may seem like a lot of extra trouble