Lately I've been thinking that perhaps the solution to the housing shortage is a technology that makes it easy, cheap, and extremely fast to build housing that is both attractive and illegal.

Uber and Airbnb were both pretty much illegal from the get go, but ultimately worked because they were incredibly popular. They forced the laws to change to accommodate what people actually wanted.

Similarly, living in tents and RVs on city streets is illegal but common because RVs and tents are so easy to set up.

No one builds an illegal fourplex because it takes a year and a million dollars. It's too expensive to shoulder the shutdown risk. But what if it took a day and $100k?