You can get a House of Luck by collecting four doubloons in the daily bonus: on the 5th day you may opt to get one doubloon instead of the free superbucks. Once you collect all four doubloons, you will be able to receive a House of Luck from the daily bonus window.
If you've accidentally lost your House of Luck after obtaining it from the bonus window, it should automatically appear in your Storage.
House of Luck gives 1 superbuck every 20 hours (more often if your neighbours help you).
You can have up to 5 Houses of Luck in your city.