system
A chat on subreddit /r/NoStupidQuestions
human
Others have pointed out that this idea is a logistics nightmare.  Plumbing alone just plain won't work without gutting the place anyway.
gpt
Plumbing, ventilation, fire hazards, and sunlight (or lack thereof) are the biggest reasons you can't retrofit a "Sears" into an apartment building. Demolition and new construction wouldn't have these existing constraints. It would be all new construction. 

Red tape, and community buy in would be the biggest hurdles outside of investment capital.