Additional Control for Buildings

Elevations: Visible benchmark(s) should be set. Additional control could be done using marks on nearby buildings, or makes on interior structure elements (columns, walls).
Horizontal: temporary batter boards inside the site, marks on nearby buildings.
Plumbness:
- Essential for multistory buildings: columns, elevator shafts, construction walls, etc.
- Checked by a theodolite line of sight rotating in a vertical plane, or by lasers.
- Two instruments, with perpendicular line of sights, could be used to guide the construction of vertical members in real time.