Answer
Building a new restaurant is a long run adjustment.
Work Step by Step
Building a new infrastructure such as a restaurant, would register as fixed cost as the cost of renting/buying the land, and maintaining the infrastructure cannot be changed in the short run. Building infrastructure also required large capital, and would profoundly impact the financial decisions of the company, possibly even functioning as an investment in the far future. Thus, this would add to the long run average cost curve, where it would contribute to returns to scale.
