The term "estimated cost" as used in this article means the reasonable value of all services, labor, material and use of scaffolding and other appliances or devices entering into and necessary to the prosecution and completion of the work ready for occupancy; provided that the cost of excavation where grading and painting, decorating and other working that is merely for embellishment or not necessary for the safe and lawful use of the building or structure shall not be deemed of such estimated cost.
(1960 Code 7-408)