The Io-16.5
It’s a Monolithic Dome with an oblate ellipse shape that has a diameter of just 16.5 feet, a height of 9 feet and a living area of 210 square feet.
Image from Introducing the Io-16.5 story

It’s a Monolithic Dome with an oblate ellipse shape that has a diameter of just 16.5 feet, a height of 9 feet and a living area of 210 square feet.