Most celebrity homes take a year or two to complete. Robert Downey Jr.’s didn’t. It took nine years, an Italian father-and-son duo, and a process of blowing up concrete like a balloon. This same style of construction was studied in a 2022 conference paper from Politecnico di Milano, Domes of Air and Concrete: Aging and Durability, calling it one of the most unusual chapters in modern concrete design.
A house built like a balloon
The building is known as a Binishell and is designed around a huge balloon rather than wood formwork or metal beams. Workers put up a nylon-covered balloon and then pour wet concrete onto it. After the concrete is poured, workers inflate the balloon with air. The balloon expands, and the wet concrete rises with it, forming a domed structure. Within about an hour, the concrete sets and the dome holds its shape on its own. This technique was developed in 1964 by Dante Bini, an industrial designer from Italy. Dante went on to construct thousands of such domes all over the world over the following decades. Later on, his son, Nicolò Bini, improved upon this concept. He wanted the domes to meet current construction guidelines and offer more design flexibility than his father's simple symmetrical designs.
