I lived in the Arcade in Providence, RI for a year. It was the USA’s first enclosed mall. The second and third floors were converted to tiny apartments.

https://www.cnu.org/what-we-do/build-great-places/micro-loft...

Not only was it the cheapest place I ever lived, it was the most enjoyable.

You can try to contact the architects https://ncarchitects.com/