- A building left unattended still degrades just like any other building. There are no exceptions when it comes to degradation!
- Buildings left unrenovated turns into a pile of "vegetation"!
- As pointed out by Dona Kiza who left this post a comment, yes buildings which has missing influence still degrades as well!
So for those of you itching to find it out for yourself, take my expensive experiment report and don't bother doing it yourself! When your building's degradation level reaches 100%, it is magically transformed into "vegetation" and you need 50 resources of each, Wood, Iron, Stone and Clay, plus an additional 24 hours of removal time! Now you do know that is expensive, don't you?
EDIT: I found out that it doesn't take 24 hours to clear the vegetation as of now September 27th 2013. It only takes 6 hours to clear the vegetation.