As-Built surveys are most often performed at the end of construction to make sure municipal and/or lender requirements are satisfied. They help determine whether on-site improvements were constructed in compliance with the specifications as outlined by the engineer during the design process. As-Built survey categories are: structural slab levels, soffit levels, slab edge levels, columns, vertical tops, column vertical bottom, popups, drainage as-built, services as-built, up-stands positions, up-stands levels and plinths positions.
A real world example. For an office building in central London, we prepared As-Built drawings in AutoCAD, using the client’s info. The drawings are then used to track the many changes that took place during the construction of the building, so they can be compared to the original building plans.