ADUs, often called “in-law units” or “casitas,” are additional units usually built alongside single-family homes, within existing residential neighborhoods.  They are fully self-contained, with bathrooms and kitchens, and are built to modern building codes.  Under state laws passed in 2019, anyone building a new single-family home in the state can elect to build an ADU at the same time, without the need for additional hearings or discretionary approvals.

ADUs are a key element of California’s strategy for addressing the state’s housing crisis.  California has a housing deficit of 2 million to 3.5 million homes, and it ranks 49th out of 50 states in the number of housing units per capita.  This need has become particularly pronounced in light of the COVID-19 pandemic, which has highlighted the number of Californians who are forced to live in overcrowded housing units due to the state’s inadequate housing supply.

To address the housing crisis, California needs to build homes quicker and at a lower cost than traditional ground-up construction allows. Building ADUs with new single-family homes is a particularly cost-effective approach.  It also minimizes impacts to neighbors and encourages ADUs that are well integrated into their surroundings.

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To learn more about California's ADU laws, click here.