Similarly, there is no evidence that the instability in the step and platform unit had existed for a sufficient time that CMH had constructive notice of the unreasonable risk of harm. Finally, there is no evidence that a truck had hit the unit on which Daenen was injured and that CMH would have discovered damage caused by such a blow in a reasonable inspection. The court of appeals recognized that this Court has held in premises cases that if there is no actual knowledge of the condition posing an unreasonable risk of harm, constructive knowledge can be based on the length of time that the condition existed before the injury. See id . We disapprove of this statement.
Constructive knowledge is a substitute in the law for actual knowledge.
In premises cases constructive knowledge can be established by showing that the condition had existed long enough for the owner or occupier to have discovered it upon reasonable inspection. To impose constructive knowledge when the owner or occupier did not have actual knowledge and would not have discovered the dangerous condition from a reasonable inspection is to dramatically alter premise liability law. This we decline to do. In sum, the plaintiff in this case failed to meets his burden of proof. There is no evidence that CMH knew or had constructive knowledge that the step and platform unit leading to its supply shed posed an unreasonable risk of harm.