Is the inspection of the building an essential formality before purchasing an immovable property held in co-ownership?

Yes, it is highly desirable to proceed to such an inspection. Indeed, the co-owners do not purchase only a private portion , but they also become owners of a fraction of the common portions. They so become co-owners of the main structure of the building, thus the roof, the outside structure of the building, the fenestration, the underground parking where appropriate, the outside parking, the landscaping, etc. It is therefore recommended to proceed to such an expertise in order to protect an investment of several tens of thousands of dollars.