I think what the competition is asking for, is that you can take the freedom to modify, expand, or refine the neighbourhood, as long as you have a solid concept and story to back it up.
In terms of the concept, don’t be afraid to take a leap to come up with something forward-looking. I mean a concept being futuristic doesn’t mean it has to be sci-fi, it can still be realistic and within the reach. In 2040, you still might not have flying cars or humanoid cyborg walking down the street, but you can have technologies or architecture that further improve our quality of life. Imagine YOU from 20 years ago time traveled to 2020, when you look at technologies nowadays, you can still tell 90% of them what they are. Now try to imagine the technologies 20 years forward, chances are you could still identify 90% of them of what they are, but they are the more advanced versions, that build upon today’s technologies. Try to build your concept around something we have today and then move it forward by 20 years. This would serve as a good starting point for something futuristic but yet still realistic.
I hope this would help you with developing your concept