Building contract: No defect when using a different building material – at least if the original building material is unsuitable

A violation of state-of-the-art technology is not a defect if the violation has no detrimental effects and no disadvantages of use are discernible.

The decision was based upon a contract for a work between the plaintiff and the defendant according to which the plaintiff owed the construction of a horizontal barrier for the waterproofing of a single-family house. Within the course of pre-contractual negotiations, one of the plaintiff’s employees advised the defendant to use a certain building material which was listed in the offer. Subsequently, such building material proved to be unsuitable for the specific purpose. The defendant used a different building material which was suited for the horizontal barrier’s construction and, after acceptance, demanded the contractually defined remuneration pursuant to Art. 631 BGB (German Civil Code). The defendants asserted there was no claim to remuneration due to the work’s defectiveness resulting from the use of the different building material.

Success of the contract for work is the decisive factor

The OLG ruled that there was no defect pursuant to Art. 633 BGB if the contractor used a building material different from the one mentioned in the offer because the originally offered building material was not suitable for the specific purpose. Likewise, there was no defect pursuant to Art. 633 (2) sentence 1 BGB, since the parties had not agreed on the material’s nature.

According to the contract’s interpretation pursuant to Art. 133, 157 BGB, it is to be assumed that the customers’ interest was to achieve the success owed under the concluded contract for work which, in the present case, is the construction of a proper horizontal barrier. According to Art. 133, 157 BGB, the plaintiff could understand the defendant in such a way that the defendant’s focus was on the owed success and thus on the interest in a successful sealing and not the use of the specific building material. According to technical experts, the owed success could in any case not be achieved with the agreed building material.

The use of an unsuitable material or an unsuitable type of construction can exceptionally become part of the contract, but only if the contractor has explained the unsuitability and corresponding disadvantages. In the present case, this case is not relevant as the plaintiff had failed to sufficiently inform the customers.

Defect because of violation of state-of-the-art technology

According to the OLG, a violation of state-of-the-art technology generally constituted a defect – however, only if such violation has a detrimental effect and results in disadvantages of use. In the present case, however, the defect did not result from a violation of state-of-the-art technology when constructing the horizontal barrier by failing to conduct a preliminary examination/building status analysis. According to the OLG, it was initially correctly established that state-of-the-art technology had been violated by failing to conduct the preliminary examination; however, the plaintiff was able to prove that, in the present case, such violation had no detrimental effect and that no disadvantages of use for the defendants were discernible.

The OLG holds the opinion – as had also basically been recognized by the Cottbus Regional Court – that the plaintiff is accordingly entitled to the due claim for remuneration, albeit – due to the lower cost of materials, at an adjusted amount.

The Senate emphasizes that this is not a case of a price adjustment as a result of subsequent increases in quantity or price increases, but rather an issue resulting from the fact that both parties made a common calculation error, so that the plaintiff must agree in good faith that the contractually agreed price be adjusted to the price the parties would have agreed if they had realized their error. According to the OLG, recourse to the calculation according to the building cost index and the formation of an average value are not appropriate in the present case. In this respect, the defendant can assert a claim for damages due to incorrect pre-contractual advice in accordance with Art. 311 (2), 280 BGB. As a result, this leads to a reduction in the plaintiff's claim for compensation.