This is possible... Just a matter of setting all wall parts to destructible (on the battle map) instead of indestructible...
The problem is that there are no animations for this.
I ones tried it and I was able to attack all wall-parts and destroy them (as in 100% damage) but the building left standing where it was since it has no other option. Because it has no animation to collapse and it has no rubble model... I haven't tried it with animations and rubble models of other wall part or buildings... So if anyone is interested in trying
