While 630 square feet may seem compact to some, for Mai Tran and her husband, Le Pham, the accessory dwelling unit (ADU) they designed for themselves was a palatial upgrade. In 2015, after an arduous Bay Area house hunt, Mai and Le purchased a single-family home for $695,000 in Albany, California. They moved into the 300-square-foot basement level, while renting out the rest of the house, with the intent to save up to build a tiny home in the rear yard.