Definition : Faulty design

Serious defect, affecting the quality of construction, which causes a degradation of the building which renders it unfit for the use for which it was intended, thereby potentially putting at risk, in totality or in part, its integrity (such as its  soundness, stability or water tightness) This type of defect may engage the legal liability of  the architect or the engineer  who has committed a fault in the expert opinions or the plans he may have supplied. It may also cause the application of contractual guarantees, including those of a guarantee plan.