That is a Phil Bolger design, a sharpie, he has several designs that can make a good camper or liveaboard.
You'll find several here:
https://www.duckworksmagazine.com/r/pla ... bolger.htmYour comment further up about using a pontoon boat makes life much simpler than building a wood boat, unless you love building wood boats.
I have a Landau pontoon that I'll be rigging for camping. Whereas I would prefer a hard top roof you can walk on, I'm going to settle for a lighter top as weight is a serious factor with pontoons. If someone is serious about a boat camper I'd suggest a tri toon to carry more weight. While you can add a center pontoon, I wouldn't have the center slide out gangplank or ramp which I need for beaching and for my boxer to get aboard.
Earlier this summer I visited a friend at a local lake area campground. His class A was parked next to a guy who hand an 18' Jon Boat modified for camping. He built a wood deck over the seats, foam and ply walls and a flat roof, the whole camper area was 10' long. Honestly, it looked hicky, but it worked for he and his wife.