Former Facebook and PayPal employee Chris Robinson is two years into an epic backyard project rising behind his home in Palo Alto: a structure dubbed the Tsunamiball.

A veteran of Silicon Valley with no nautical or construction experience, Robinsin met his wife in Fukushima and, after seeing the disaster unfold, set to work trying to solve the issue of tsunami-proof architecture.

His capsule is 22-foot-long, 10-foot-wide, 8.5-foot-high and built of plywood and epoxy, envisioned in Adobe Illustrator, vetted by engineers then slowly constructed by hand. The inspiration? Seaworthy escape pods and spherical treehouses. You can see a video of the building process over at Wired – additional videos available on Tsunamiball.com.

So far he has finished most of the hull but still needs to add buoyant insulation, a structural keel and an electric motor fueled by solar batteries. While his own California home is unlikely to ever go underwater (at least not literally), Robison plans to test the seaworthiness of his creation in the nearby Pacific Ocean, and then perhaps rent the place out on AirBNB. Maybe it can also serve as a prototype for a new kind of disaster-resistant design for coastal areas.