His design for his parents' house in Berkeley, California, is known for its unusual round shape and its structural concept. The home, sometimes called "Ojo del Sol" ("Eye of the Sun"), is also known as the "Fish House" and, according to Tssui, is based on the anatomy of a tardigrade. The materials used in making the Ojo del Sol include inexpensive and recycled materials that draw inspiration from the Cholla cactus, which is virtually fireproof. Tssui designed the house with the goal of making it the "safest house in the world," intended to survive fires, earthquakes, flooding, and termites.