ADU – Accessory Dwelling Unit

New laws taking effect January 1, 2021 enable more homeowners to build ADUs and in many cases make obtaining permits much quicker and less expensive. ADUs are also called: granny flats, in-law units, backyard cottages, second dwelling units, etc.

Automatic Approval: Cities/counties must permit certain categories of ADUs without applying any local development standards if proposed on a single-family lot. ADUs eligible for this automatic approval include:

  • An ADU or JADU (junior ADU) converted from existing space in the home or another structure (e.g. a garage), so long as the ADU has exterior access and setbacks sufficient for fire safety
  • A new detached ADU under 800 sq ft in size, 16 feet in height, with 4-foot side/rear setbacks
  • Both of the above options in combination, creating one internal JADU and one detached ADU

Reduced Costs for Developing ADUs

  • ADU applications must be approved within 60 days, without a hearing or discretionary review
  • For ADUs permitted by 2025, cities/counties cannot require the owner to live at the property
  • No impact fees are required for ADUs under 750 sq ft; proportional fees apply to larger ADUs
  • An ADU can be developed at the same time as a primary dwelling, under most of the same rules
  • A city/county must delay code enforcement on an unpermitted ADU to allow it to be legalized
  • Single-family HOAs must allow the development of ADUs, subject to reasonable standards
  • Single-family homeowners can also develop JADUs – units under 500 sqft within a residence

Previously many cities restricted the construction of ADUs to single-family lots larger than 8,000 sq ft.

More details are provided on my ADU – Accessory Dwelling Unit web page .

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