If you want to build a city of the future, you need futuristic buildings as well. I made a catalogue with all buildings available for downloading, like grownable apartment buildings and spacecrafts. Because there is no reason to re-write the list, I'll give you only the link to check it out.
 
CLICK HERE   Of course there are more addons as well, like automata and extraterrestrial maps. Feel free to share with us what mods are recommend for making a future city.