Because cities are mainly grid based, and because I build my roads and government buildings on baseplates, we could replace those baseplates with city lots, which would function with ownership under the city.
The only person who is capable of editing the "city" would be the mayor.
This way, we could designate specific buildings as in-destructable, and others as editable upon the mayor's request.
Any brick destroyed on the city lot would go directly into the treasury again, so mayors could demolish the terrible dictator statue of the previous mayor, and regain the city's lost dollars.
If this system does manage to sprout correctly, we'd want to begin the city with basic infrastructure.
Easy stuff, really. Sounds like a lot of fun.
Basically provides all of the features that Sim City presents.