multi hull house boat design

[pontoon flyer]

Hi there to all, I posted this post under boat design by mistake it seems, so posting it here. I am trying to build a multi hull fiberglass wood combo that can float on a river, strong enough to cater for 2 decks, 12 to 15 meters long and 4 to 5 meters wide, have 1 or 2 engines, speed not a requirement. I would like to build the hull in sections and do final assembly in the water due to limited space at home. I have got hold of plans but they do not cater for sections, is there a plan out there that does ? I don't want a barge. if anyone can help, it will be much appreciated