One of the most common reasons for owning an ADU is the opportunity to generate additional income to help cover the costs of buying a house and other household needs. ADUs used as rental units generally cover the costs of acquiring and financing the ADU. Once the loan used to buy the ADU is paid off, the ADU can provide reliable additional income to a household. 

The price of a new ADU is an important part of the return on investment. Standardized ADUs are often lower cost than custom built ADUs, and therefore have a shorter payback period and are able to realize the income earning potential faster than more expensive ADUs.