Article 689 of Civil Code

1 - If the contract for work is concluded on the basis of an estimated bill of quantities, and during execution it becomes apparent that this estimate must be substantially exceeded, the contractor must promptly notify the employer thereof, specifying the increase in consideration entailed by exceeding it; otherwise, he shall forfeit his right to claim that increase. 2 - In this case, the employer may withdraw from the contract for work and stop execution, provided that this is done without delay, while paying the contractor the value of the work completed, assessed in accordance with the terms of the contract, without compensating him for what he could have earned had he completed the work.