Under the law, contractors are obliged to warn their client of additional costs arising from an addition or change desired by a client. If a contractor does not do so, he is not entitled to reimbursement of these costs, unless the contracting authority should have understood the need to increase the price of these costs on its own. Nevertheless, there is an exception to this rule, according to a recent ruling by the Supreme Court
https://kennis.bierman.nl/blog/meerwerk-de-waarschuwingsplicht-van-de-aannemer-verduidelijkt
MEMORANDUM
Relevant Law
In Czech law, the Civil Code and the Business Corporations Act are relevant for determining the scope of duties and responsibilities of the statutory body.