Alright, so I've noticed that buildings collapsing regularly isn't lethal unless some unfortunate player was high enough to die of fall damage.
I thought of this: Anyone hit by the building as it falls takes large amounts of damage (50-100, depending on how they're hit and/or size of the building) as the building collapses?
A good thing about this is that one would be able to kill possibly half a team by destroying a building successfully. This will also make players have better thought put into protection of their constructs.
Just a thought, open to other opinions!
(Also just saved you all from 666 topics. Thank me later :3 )