The best way to upgrade devices is by doing a backup of your OLD iPad by synching it to iTunes prior to setting up your new iPad. Then, when you setup your new iPad you can choose “restore from backup.” This is the only method that will save all your custom settings and projects.
As far as in app purchase of rooms, these can be retrieved with our without using the backup method by going to the help (? icon) menu in the app and choosing “restore purchases.” Make sure you are connected to WiFi and that you are signed into the app store app on your iPad using the same apple ID that you purchased the app with.
