the best way to ruin a house beyond repair is this...

get your self couple of bags of cement and mix alot of water to make it a bit light...

drop it down every open pipe in your house (sink,toilet,bathtub,sewer pipes,main water pipe) then let it set

the repair will cost the bank more than the house itself... replacing every pipe in the house means they have to redo the house...

ahaha... i think they can charge you if you fuck up the house... duno