best is 540 and even then its hard. the rail to do it on is the long one on an angle on the right side of coc. the end of the rail is positioned at the top of the landing for max air. if you have time move all the rails to that position and then you will be able to flip off of them
physics would dictate that you would have a lot of time to spin when leaving a two story roof. however, gnarshmallow physics tells us that a two story house is only 3 feet high.