Our GUI already has quite a lot of buttons, I wonder if adding this might be too much. What do you think about having a game setting that applies to all buildings? There is now rubble in the svn version of the game. This is a purely graphical effect. When you kill units are destroy buildings currently there is loot gained, this is not obvious though. One suggestion has been to block further construction for a time period where the rubble is. Roads are unlikely.