What Are ADUs and Why Are They Gaining Popularity?

Accessory Dwelling Units (ADUs), also known as granny flats, in-law units, backyard cottages, or secondary units, are becoming an increasingly popular solution to the housing shortage. These small, independent residential units are built on the same lot as a primary home, offering a flexible and efficient way to increase housing options.

While local ADU ordinances are optional, interest in them has skyrocketed. More cities, counties, and homeowners are embracing ADUs as a practical approach to expanding housing choices and affordability. The California Department of Housing and Community Development (HCD) leads the way in supporting local ADU policy and development.

Please note: As of March 25, 2024, due to the passage of Senate Bill (SB) 477 (Chapter 7, Statutes of 2024), the Government Code sections relating to CA State ADU and Junior ADU (JADU) laws have been re-numbered.

Benefits of ADUs

ADUs offer numerous advantages for homeowners, families, and communities:

• Affordable to Build: ADUs are cost-effective since they don’t require purchasing additional land or investing in large-scale infrastructure, structured parking, or elevators.
• Potential Income Source: Homeowners can generate rental income by leasing out their ADU.
• Lower Construction Costs: ADUs are typically built using wood-frame construction, which is significantly more affordable than materials used in larger multifamily buildings.
• Support for Extended Families: ADUs provide a way for families to live close to each other while maintaining privacy and independence.
• Comparable Living Space: Many ADUs offer the same amount of space as new apartments or condos, making them ideal for couples, young professionals, small families, or seniors.
• Flexibility for Changing Needs: Homeowners can use ADUs to accommodate aging parents, adult children, or caregivers—allowing for multi-generational living while ensuring comfort and care.

ADUs continue to prove themselves as an innovative housing option —
offering both versatility and value in today’s housing market.