When instructed to carry out a topographical survey, a framework of control positions is established throughout the site. The co-ordinates of these positions (in easting, northing and height) are then calculated and used to produce the final survey of the site.
This survey drawing can then be used as a base plan for the proposed development, therefore keeping the mathematical relationship between the existing site survey and the proposed drawing.
By using the aforementioned control positions, we can return to site to set out the position of the designed layout within required tolerances.