Gagmuk's post reminded me.
Long ago on the other thread that has gone on for years was a suggestion similar to this. It was to allow us to build on our current house. There were many great ideas and some of them wouldn't even require much in outside changes. It was let us add on in the attic, add a few floors underground, expand hobbit homes into the hillside, lots of ideas that wouldn't require exterior changes. Right now loading a neighborhood is like loading a house, all the basic are the same with just hangers different. Having new rooms could be like that with little changes.