Communities & Environment > Planning > Housing > Housing Policies > Housing Policy Toolkit > Accessory Dwelling Units

Accessory Dwelling Units

Accessory Dwelling Units (ADUs), also known as second units, granny flats, or in-law units, are dwellings that exist on a lot with another house, and can be either attached or detached from the main house. ADUs are a sustainable way to add flexible, affordable, and diverse housing options with minimal impacts on existing development patterns and infrastructure.

In recognition of the importance of this housing strategy, in 2016, California adopted new laws intended to make it easier for property owners to create ADUs, mandating that all local agencies adopt an ADU ordinance that is consistent with the new requirements by January 1, 2017. The State law requires local jurisdictions permit ADUs without discretionary review, and provides guidance as to parking requirements and fees. In the instance of a local jurisdiction that has not adopted a local ordinance, the state legislation will prevail.

Good News on Expanding Financing Options for In-Law Units

In response to the passage of land use: zoning legislation (SB 1069 Wieckowski) on accessory dwelling units (ADU) in 2016, the California Housing Finance Agency recently announced that it has revised its guidelines so first-time homebuyers may apply rental income from an ADU toward loan qualification. The move will help more low and middle income families qualify for their first home and codify the role ADUs can play in addressing the state’s massive housing shortage.

Legislative Updates/Briefing Materials:

Model Ordinances and Resources: