A natural or legal person who has carried out or had work done on the property sold, such as a promoter or building contractor. Article 1729 of the Civil Code of Quebec provides that where a defect in property sold by a professional seller manifests itself prematurely in relation to property of the same kind, the defect is presumed to have existed at the time of sale by the professional seller in question. However, this presumption may be rebutted if the defect is due to misuse of the property by the buyer.