it really doesnt need to be THAT high, maybe half a foot at the lowest just to let ventilation and cold air to drop??? also, i dont know how far you are with your project so it might be too late to mention this now put have you thought of building a duck tractor? heres a link to one i would like to build this summer. and i read somewhere if you plan to keep the ducks in the enclosure for a lot of the time, each average duck needs approx. 1.5 meters squared of space for themselves. i hope that can help you determine how big you should have your house!!!