TreeHugger has shown many examples of where people live on top of the shop, which has been common since there were shops in the first place. Dezeen shows a lovely little house in Japan, where Tokyo designers Do Do have created a lovely office for a graphic designer, with a small but very efficient apartment above. It also just happens to have a special bridge for the cat.
"The husband, who is a cat-owner, hoped his house to be creative both for his work and cat, and my aim was to create a comfortable living space in this busy district of Tokyo", the architect tells Dezeen.
Architect Mark Hogan notes that the cat bridge is probably superfluous.
I personally prefer the CTS (Cat Transit System) built by Jillian and Jeffrey. See other catitecture in related links below.