I think this could turn out to be amazing, it looks lovely so far. I'm really interested in seeing If i can get this to blend into my game.
The only thing I was thinking was perhaos you could make some simple, plain building shapes that people can fit together - I know you have two types of house on there already(4 if you count 2 colours each) but maybe just some plainer ones that tile together more easily? Other than that I can't think of anything!
Great Work, hope it's finished soon!