My guess is that "html" really means "folder full of static stuff," and each project needs to be in it's own subdirectory called "home." Confusingly, Apache or whatever might be config'ed to read directories indexes from home.shtml.

The first html is the generic static assets folder, and the second is the local projects' folder full of assets.

Poor developers never had a chance.

www.nyc.gov/html/housinginfo/html/home/home.shtml

www.nyc.gov/html/dob/html/home/home.shtml

www.nyc.gov/html/planyc2030/html/home/home.shtml

etc.