S.L. 601.3 ст. 256Duty on contractors.

A contractor shall desist from executing a modification which requires the approval of the Director unless the contracting authority provides him with a written confirmation of the said approval. If the contractor carries out the modification nonetheless, he shall be deemed to have acted in bad faith and thus he shall not be entitled to any compensation with respect to that modification, so long as such modification was not approved by the Director or when the contracting authority proceeded with the modification without seeking the prior approval of the Director. Any payments received by the contractor in this regard may be restored in the same manner as provided in regulation 255.