I love the building designs, but as always things as they are now can always be made even better. The more options, the more fun the game becomes.
So my suggestion is a new range of residential building designs. Perhaps as an option, a player can change not just the colour or what a building is made but it's design. We can already edit the palace in a number of ways, so what if the same could be done with residential buildings. In fact even prisons among other buildings.

Like changing them from tropical design to European for example. Also as an optional extra and for pure fun, add an Elven design to them. Like a white or light blue circular design.
Just a thought.