What if the owner who lives on the top floor regards the public rooftop as private property?

First of all, we must make sure that the rooftop is a public part, and the right belongs to the owner of the whole building, not any one or two (including the top floor tenant \ owner).

1\ Notify the property. If it is really an illegal building, the property will issue a rectification notice. Note: the authority of the property is limited, and it cannot be forcibly removed, because the property has no law enforcement power.

2\ If the property does not issue a rectification notice or the person who built the illegal building refuses to rectify, directly find the urban management department of the local street or the street office under the Real Estate Bureau. They have the right to enforce the law.

3\ If these two departments do not act, they will directly bring a lawsuit to the court, demanding that the person who built the illegal building stop the infringement and restore the original state. If the building is really illegal, the court will support you. If the restitution is refused, it should be enforced by the court.

4\ If you can't do it again, find the news media to expose it and create pressure on public opinion.