Building an ADU can help increase property value in a number of ways. First, adding an ADU can provide more living space for a family, which can be a major selling point for buyers. Second, an ADU can provide rental income potential, which can be attractive to investors. Third, building an ADU can add value to a property by increasing the overall size and square footage. Finally, an ADU can be used as a home office or studio, which can also add value to a property.