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Current through 2026Gov. Code §§66317 & 66335

California ADU Permit
Milestone Screen

Calculate one statutory review milestone at a time. This screen does not forecast construction, utility review, certificate-of-occupancy timing, or the total time needed to finish a project.

Who it's for: California architects and homeowners tracking ADU permit review milestones between permit submittal and construction start.

How to use this calculator

1
Choose one milestone
Completeness, approval/denial, and appeal use different clocks.
2
Use the correct received date
Enter the date the agency received the application, completed application, or written appeal applicable to the selected milestone.
3
Verify conditions
Business-day results require the agency calendar. Decision results require the existing-versus-proposed primary-dwelling context and any exact applicant-requested tolling days.
4
Confirm the result
Use the output as a statutory planning screen, then confirm the agency record and current law.

The formula

Completeness: 15 business days after the permitting agency receives an application or cured resubmission. Decision: 60 calendar days after receipt of a completed application where an existing qualifying primary dwelling is on the lot, plus any applicant-requested tolling period. Written appeal: final written determination no later than 60 business days after receipt. A concurrent proposed primary dwelling can make the ADU/JADU decision milestone event-based rather than date-certain.

Worked example

Example
If an ADU permitting agency receives an application on Monday, March 2, 2026, and March 23 is the only applicable weekday closure in the interval, the entered-calendar completeness milestone is Tuesday, March 24, 2026. If it receives a completed ADU application for a lot with an existing dwelling on June 1, 2026, and the applicant requests five days of delay, the planning date is August 5, 2026.

When this estimate will be off

  • This is a calendar screen, not legal advice, a permit, authorization to build, or a project completion forecast.
  • For business-day milestones, the user must verify the actual reviewing-agency calendar; weekends alone are insufficient.
  • The decision clock requires a completed application and an existing qualifying primary dwelling. A concurrent proposed dwelling application can delay action until the agency acts on that primary-dwelling application.
  • Applicant-requested delay tolls the 60-day period. This screen does not infer other timeline disputes, correction history, agency receipt, completeness, coastal permits, utilities, building/fire review, appeals procedure, or local administration.
  • Government Code §66317 expressly states deemed approval for the ADU decision path; the cited §66335 JADU text does not contain the same decision-path sentence, so this screen does not add it.

Frequently asked questions

A common mistake: This is a calendar screen, not legal advice, a permit, authorization to build, or a project completion forecast.

No. It calculates one limited statutory review milestone. Design, corrections, utilities, building and fire review, other permits, construction, inspections, and certificate of occupancy are outside the result.

Not safely. A business-day count must use the reviewing agency’s actual calendar, including applicable weekday holidays or closures. The screen therefore requires calendar confirmation.

Do not assume that. The statute requires completeness notices and written deficiency information, while the decision period runs from receipt of a completed application and applicant-requested delays toll it. Preserve the agency record and obtain advice for a disputed chronology.

No. Section 66317 contains a deemed-approval provision, but applying it depends on verified facts and records. Confirm the status in writing with the permitting agency and obtain qualified legal advice before relying on it.

Sources

  • California Government Code §66317 — current ADU completeness, 60-day decision, applicant-delay tolling, written denial, and appeal provisions; amended effective January 1, 2026
  • California Government Code §66335 — current JADU completeness, decision, tolling, denial, and appeal provisions; amended effective January 1, 2026
  • California HCD Accessory Dwelling Unit Handbook, March 2026 — official permit-application and permitting-agency guidance, pages 33–35

Sources and review record

Sources and method basis

Limitations

  • One statutory milestone at a time; not legal advice, authorization to build, or a total-project forecast. Business-day output requires the user-verified agency calendar, and decision output requires verified primary-dwelling context and applicant-requested tolling.

This free California ADU Permit Timeline is built and maintained by DataDrivenAEC, using the relevant codes and standards. It does not substitute for professional judgment.