The Challenge of Using Builder’s Square for Accurate Setting Out The dilemma of relying solely on a builder’s square for setting out is a major concern for construction engineers, builders, and surveyors who demand accuracy on site. On every project, you want: • All four corner angles to be perfectly square at 90 degrees • Equal measurements on the right and left, front and back • Matching diagonals for proper geometric confirmation Achieving all of these with only a builder’s square is time-con