Even stories set in modern day take a certain amount of world building – even if only to set the scene for the reader.
“Why is J.R.R. Tolkien’s Lord of the Rings trilogy so compelling? How about The Matrix or Harry Potter?
“What makes these disparate worlds come alive are clear, consistent rules for how people, societies — and even the laws of physics — function in these fictional universes.
“Author Kate Messner offers a few tricks for you, too, to create a world worth exploring in your own words.” – YT
I think she touched on an important thing here in that you need to really know your world if you want to write fiction people will love.
Source:
http://www.webtvhub.com/watch-how-to-build-a-fictional-world-kate-messner-ted-video/