Well . . . at least he's not sitting on his couch watching re runs of the Gong Show.

This thing is round right? Capsule shape. I would like to read more about how the designer thinks this vessel will respond when it is hit hard by waves and debris. Clearly this thing won't remain upright when it is shoved along by water over a debris field.
It is likely to roll and tumble along, pushed under even although hopefully the buoyancy will keep it float on top of the churning water.
Benches won't cut it. The inhabitants will be smashed to pieces inside the intact capsule. I imagine strong tight fitting seats are needed with 5 point harnesses because the occupants will be in for a hell of a ride.
A good test would be to throw the capsule into the surf on a beach with 2 meter waves. Let it be pushed and rolled along a bit.
No lose items inside and if they test it this way. Please put a GoPro camera inside. Love to see the effect. Ha ha ha

A tough conventional boat looks like a better option but a submersible bunker looks safer as well even if digging out is problematic. just make sure the door opens in and you have good cutting tools.

Another option is to move to a higher place, or be prepared to drive towards higher area.

kitchen, toilet, beds,... how long is he planning to drift with tsunami? ridiculous design :) Drop it from Niagara Falls with some G-force sensors mounted inside, that would be interesting. I would rather prefer something more like space capsules rather than this tree house :)

If he had used all that time and money to build a BOAT instead of a helpless floating tube he might have actually had something that was useful for the 99.99999% of the time when a tsunami is NOT hitting.
Anyone inside that thing he built would be killed or severely injured after rolling around and banging into everything inside. The only way I would ever consider going into something like that would be if it had race car harnesses built into the sides so I could strap myself in -- and of course everything in it would have to be securely attached to the structure as well so it doesn't break off and kill me while I am stuck in the harness.
This is one of the most ridiculous wastes of time, money and energy I have ever seen on Gizmag. I sure wish I had had this guy's money to build a boat because I could have built a great one for what this guy has invested already.

A sphere would be the best design

Do people actually read before they criticize? "bench seating with five point harnesses". The back seats of ordinary cars are bench seats.
Robinson deserves credit for his ability to translate an idea into (hopefully) functioning reality, but it's taking the long way around. It would be easier to accomplish the same thing by starting with a commercially available life raft & reinforcing the hull.
That leaves the question of why someone would want something so specialized to begin with. Palo Alto is located on the Bay side of the San Francisco Peninsula.

it will take so trial and error, I can see where it may need some add weigh to lower the center of gravity. And could be incorporated to a building design

You are a master craftsman, the detail is outstanding....a yellow paint and play the "Beatles" "yellow submarine" and we're all set ! LOL just kidding, Truly impressive build.