A topographic survey locates all surface features of a property, and depicts all natural features and elevations. In essence it is a 3-dimensional map of a 3-dimensional property showing all natural and man-made features and improvements. Specifically, it shows their location, size, height and any changes in elevation.
As-built surveys, also commonly referred to as record drawings, provide formal documentation of exactly how a project was installed. They document the actual results of the construction project rather than the planned layout shown in the project design and are critical for project closeout.
A new construction survey is necessary before establishing structures on a parcel of land, including roads, utilities and buildings. This type of survey utilizes both vertical and horizontal grading.
Vertical positions are verified by differences in elevations in comparison to a specific location on the property, which is known as the benchmark. Horizontal positions are determined by distances between structures.