21. (1) The expressions “estimated cost of the works” and “actual cost of the works” shall mean the total expenditure by the client for the completion of the works for which the firm provides professional services and for which it is responsible, including the cost of fixed accessories required for occupation, overheads, administrative expenses, profits of the contractor and all applicable taxes.
(2) If the client supplies labour or materials at prices lower than current prices, or if used materials are employed, the estimated or actual cost shall be that of all the materials and labour required to complete the work, as it would have been if all the materials employed had been new, and the labour had been paid at the market place at the time when the work was ordered.
(3) The following are excluded from the “estimated cost of the works” or the “actual cost of the works”:(a) fees or expenditures of firms awarded contracts for the project;
(b) works required for any process of production, fabrication, processing or transformation contained in the work;
(c) cost of acquiring immovables;
(d) cost of demolishing buildings, unless they form part of the construction contract;
(e) cost of borings, tests, analysis, checking and supervision of materials;
(f) cost of moving private or public utilities carried out by their respective owners;
(g) expenses resulting from errors or omissions by the firm;
(h) the cost of works of art.
(4) The estimated cost may be revised at the time of approval of preliminary and final plans and specifications, but may not exceed the estimated cost provided by the contract, unless it involves changes to the program specifically required by the client.
(5) Where, following the opening of tenders, the lowest acceptable tender exceeds the revised estimated cost, the client may require that the firm revise wholly or partly, at its own expense, the plans and specifications, on condition that such requirement be specifically permitted by the contract.