No, seriously, why do they? It's not like the construction workers don't get paid their wages if they aren't given such projects, and, unless you are buying the resources from overseas, the only cost for the construction materials for the state is wages/salaries of the workers who are involved in the relevant processes.
Am I being swindled?
Which implies that there are no other cities in your country.
Another person has explained to me that that is, apparently, the case or something similar to that is.
All of the land that you see/can build on is your country. If there are no other cities, then there are no other cities. If you haven't build a construction industry, then there isn't one.
If I'm not mistaken, the game is essentially about starting your own soviet republic under the USSR (and presumably handwaving away the idea of non-monetary cooperation between soviets) so yep, no pre-existing anything.
I think the premise is you're a tiny as fuck micro-nation in the Eastern Bloc that was literally just a few villages before WWII, so yeah you're improving a lot from the rest of the USSR.