My children were in pre-school several years ago in a Jewish program and the woman who ran the program asked me to make a Noahs Ark for the school kids to play with. She had a basic plan from one that someone had done at another school and she wanted it. I couldn’t stand the plan, so I made my own.
The top of the Ark is about 2’10”. The boat is 2’ tall, 4’ wide at the top, and 10” deep. The wood is plywood with rounded/routed edges. The house on top is 8”x24”. Because this isn’t a very heavy piece I added a wood support beam to the top of the middle shelf; I also used 2 – 2×6’s joined together and painted blue, then screwed to the bottom of the boat to give some rigidity and weight to the base so the kids won’t accidentally knock it over. The whole thing was finished with some water-based polyurethane.