Increasing your Shelter Level is a key component to progressing in Shelter 69. Your Shelter Level determines what rooms you can build, how many of them, and what level they can be upgraded to. Those rooms determine the maximum Character Level, Equipment Level, and Trust you can have - along with how quickly your base acquires resources and how many of them you can store at a time.
Shelter Level is increased by completing a set of Shelter Level Tasks.
Current Maximum Shelter Level: 40