They could be leasehold improvements. The cost of the build-out of the interior of the rented space. Improvements, whether by a property owner or a leasee, can't be written off as an expense and must be depreciated. Then all depreciable assets have to be reported to the property tax collector. Those are usually always forfeited on move-out. Can't take the walls out, IMO.
ETA: Certain LH improvements are exempt, so nix that comment about the walls.
http://www.qpublic.net/franklin/tppfaq.html
6. Are leasehold improvements tangible personal property?
If an improvement is of a permanent nature that cannot be readily replaced, or if removing the improvement would cause substantial damage to itself or the real estate, it is NOT considered Tangible Personal Property.
If the improvement can be easily removed without damaging itself or the real estate, then it is considered Tangible Personal Property[