[Oren]

Whoa, Aoshi. You're making my head hurt.
In my opinion, I don't feel that one (be they Shinigami or human) would be capable of using a Note to "kill" a building. It would not be in a Shinigami's interest to kill something which he could not benefit from, i.e. gain life span.
A human could destroy a building using the Note if he should control another human for a certain time, and dictate that human to destroy a building before dying as written.
As far as your musings that someone could be crazy enough to believe a building were "alive".....well, let's hope someone like that never gets their hands on a Note. They'll be killing off our computers as well!!