From a first reading of this Article, it is apparent that the legislator did not take the trouble to deal with the case in which the parties have clearly and explicitly fixed the price for the work or the service. Such a case would not present any problem and would be the manifestation of the will of the parties to agree upon all elements necessary. This draws our attention to increasingly frequent cases in which, for one reason or another, the parties have not established the price or stated the method for calculating it. In such cases, which are just as frequent as they are anomalous, certain mechanisms for establishing the amount of the price come into play which save the contract from being declared void.

There is however, discussion about whether the construction contract retains its commutative nature or changes into an aleatory contract if the mechanism for paying the price for the contracted work has not been established or, even, cannot be established. It is well known that “aleatory contracts” in the true sense are only those contracts in which, at the time the contract is entered into and the relationship is created, there is uncertainty about the performance to be supplied by one of the two parties or at least its extent, i.e. the nature and the quantity of the object of the performance and not its economic value, which may constitute only a reason and, as such, irrelevant1. It is clear that if this is the definition of an aleatory contract, the construction contract retains its nature of “commutative contract”, since the extent of the performance of the two parties is always established, or at least can be established on the basis of objective criteria and not depending on future and uncertain facts.

Therefore, as far as the construction contract is concerned, even if of a different nature, the obligations of both the contractor and the client