Some topics to consider:
- The number of citizens to level up the city only allow big guilds to reach the highest levels(at least, in the current alpha).
- People who build the house outside of the city are totally safe and don't risk anything, so people don't construct houses inside.
- The city is really small to construct all the buildings and houses.
Some ideas to fix the former topics:
- The citizens who build their houses inside of the city give more residents to the city or as big the house is, bigger is the resident number.
- Increase the size of the city.