SE isn't happy with the part of the player base that already modifies the game's art assets in questionable ways and then share it online. They're not likely to offer something that will make that even easier to create.

If you want to build a spectacular mansion on your client that's just for you to enter, try something like The Sims. A quick google search shows that there are some housing design games even for mobile phones, making it easy to create the house of your dreams while you wait in queue.