Terrestrial laser scanning used to be reserved for projects where accuracy was worth an unusual premium. Equipment and processing costs have fallen far enough that the calculation has inverted.
A scan of a 60,000 square foot existing building runs a small fraction of what one serious field conflict costs to resolve during construction, once you count the change order, the schedule impact and the coordination time. On a water reclamation plant upgrade last year, 340 scan setups produced a point cloud that carried the entire design. Process piping tie-in conflicts in the field: zero.
The secondary benefit is arguably larger. The point cloud does not expire when the project ends. It becomes an asset record the owner keeps, and the base drawing for whatever gets done to the building next.