We have a somewhat odd situation where we would like to draft an agreement with a private property owner for them to donate some artwork to the city. The artwork is on the side of their (privately-owned) building but faces out to a public pathway that is city-owned. We would need to have access to the inside of the building occasionally for maintenance of the artwork since it has lighting components that are housed in the building. The owners are amenable to working with us and don't want responsibility for the artwork anymore but are fine with leaving it where it is since it was built for the specific site. Our concern is writing an agreement that would protect the artwork to some degree from being removed without notice or, in the case the building sells (not sure that is possible to plan for). Does anyone have any examples of agreements from a similar situation?

Thanks,

Megan