Construction surveying is the translation of a contractor's set of construction plans into a physical representation on the project site. It not only includes surveyors locating and setting physical markers, usually a lathe, pin, or survey stake in a horizontal position, but also communication to the contractor as to the actual elevation and the required cut or fill necessary to obtain the design elevation. It also includes the checking of improvements and temporary construction items placed to construct those improvements to verify the horizontal and vertical location to the construction plans.Construction stakes are not set at their actual location.
Instead surveyors set an offset stake with a lathe outside of the construction limits. The lathe includes the necessary information, usually a "grade" and an "offset" that allows the construction workers to build the improvement. This allows the improvement to be constructed without disturbing the stake. The offset is a horizontal distance measured from the construction stake, and the actual improvement being referenced by the lathe. The grade is a measure of the necessary "cut" (lower the existing elevation or remove material) or "fill" (raise the existing elevation or add additional material) between the existing and design elevations. The contractor and the surveyor coordinate the location of the construction stakes so that they will not be disturbed during construction .