The rule of law is a great thing. It's a shame when short sighted people enforce the letter instead of the spirit of the law as that undermines order in the long term.
Probably something along the lines of "Do not build dangerous things in your yard, were they could fall on people passing by. Also no ugly stuff."
Which could or could not be relevant toward that bookshelf.
Small minded people are generally attracted to this kind of power, so we get far too much of the later.