You can transfer your progress with unlocked buildings by syncing the game between your old device and your new one, either via Facebook or your Apple ID data (for Apple devices).
To do so, you need to log in to your Facebook account in the game on the old device, and then do the same on the new device - the progress should synchronize.
Please note that you need to complete the tutorial levels in the game first. They include the first 4 houses in the city.
It is also possible to synchronize your progress via Apple ID data in case you are playing on an Apple device. If you had that type of synchronization in your previous game, then you can use it again to restore your gaming progress in your new game on the same platform.