California law requires the City of Santa Clarita or LA County to approve or deny a complete ADU application within 60 days. Since 2026, the agency must also tell you within 15 business days whether your application is complete. In practice, most delays come from incomplete plans and rounds of corrections, not from the deadlines themselves.
What deadlines does state law set for ADU permits?
| Step | Deadline | Source |
|---|---|---|
| Completeness check | 15 business days to say whether the application is complete and list anything missing | SB 543 (2026) |
| Resubmitted application | 15 business days to review it for completeness | SB 543 (2026) |
| Approval or denial | 60 days after a complete application | State ADU law |
| If the agency misses the 60 days | The application is deemed approved | AB 3182 (2025) |
| Public hearing | Not allowed; a compliant ADU gets ministerial review | State ADU law |
The 60-day clock covers review of a complete application. Time you spend fixing plans after a correction notice doesn’t count against the agency.
How does the permit process work in the City of Santa Clarita?
This applies in Valencia, Newhall, Saugus, and Canyon Country.
- Planning review. The Planning Division reviews every ADU and JADU first. Building & Safety won’t start plan check until Planning clears the project.
- Building & Safety plan check. You can submit two paper sets or upload plans through the city’s eService portal.
- JADU covenant. For a Junior ADU, a deed restriction covenant must be recorded with the LA County Registrar-Recorder before the building permit is issued.
- Permit and inspections. After plan approval, your contractor pulls the permit and schedules inspections.
Questions go to the Planning Division at (661) 255-4330, 23920 Valencia Blvd, Suite 140.
How does the permit process work in LA County areas?
This applies in Stevenson Ranch, Castaic, Acton, and Agua Dulce.
- Check your parcel on LA County’s Z-NET map.
- Regional Planning review of your site plan for zoning, setbacks, and height. For a JADU, a recorded covenant is required.
- Public Works Building & Safety plan check, typically submitted online through EPIC-LA.
- Permit and inspections after plan approval.
What should you check before you apply?
A short feasibility check saves the most time later:
- Jurisdiction and zoning: confirm whether the City of Santa Clarita or LA County reviews your parcel.
- Space: confirm the ADU fits with 4-foot side and rear setbacks. See ADU size, setback, height, and parking rules.
- Overlays: hillside, high fire hazard, flood, and oak trees each add requirements.
- Utilities: electrical panel size, sewer or septic, and water service.
- Fire sprinklers: needed only if the main house requires them. See ADU fire sprinkler rules.
- HOA: read your CC&Rs and plan to submit to the HOA at the same time.
See is my lot eligible for an ADU? for a step-by-step self-check.
What goes in an ADU permit plan set?
A typical submittal includes:
- A site plan showing the ADU, setbacks, and existing structures
- Floor plans and exterior elevations
- Structural details and calculations
- The Title 24 energy compliance report
- Utility plans for water, sewer or septic, and electrical
Check the city’s or county’s current submittal list before you submit, since missing items restart the completeness review.
What inspections happen during construction?
After the permit is issued, inspections typically follow the main stages of work: foundation, framing, rough plumbing, electrical, and mechanical, insulation, and a final inspection. Your contractor usually schedules them. A failed inspection adds time until the item is fixed and re-inspected.
What causes ADU permit delays?
- Incomplete applications. Missing site plans, structural calculations, or the Title 24 energy report send the application back.
- Correction rounds. Each set of plan check comments adds time until they’re resolved.
- Oak trees. City lots with oak trees need Urban Forestry clearance before development.
- Fire hazard zones. Access and fuel modification requirements need to be shown on the plans.
- Septic systems. Rural county lots often need an Environmental Health review, and sometimes a percolation test.
- HOA review. It runs on its own timeline, separate from the city or county.
How can you keep your ADU permit moving?
- Confirm your jurisdiction first. City and county use different offices and ordinances. See the service area page.
- Confirm size limits early. Designing to the wrong size limit means redrawing plans. See ADU rules and basics.
- Submit a complete package. Include structural calculations and the Title 24 report the first time.
- Start HOA review at the same time as the city or county review, so one doesn’t hold up the other.
- Answer corrections quickly. The faster your designer responds, the sooner review resumes.
- Consider pre-approved plans in LA County areas. They shorten plan review, though they can’t be modified.
Want help getting started?
Call (661) 486-8393. If no one answers, leave a voicemail with your name, phone number, address, and the type of ADU you want. We’ll pass your details to a local ADU contractor, who will follow up with you directly. There’s no obligation to hire.
ADU permit FAQs
How long does the City of Santa Clarita have to approve an ADU?
State law gives the city 60 days after a complete application to approve or deny it. The city must also tell you within 15 business days whether your application is complete.
What happens if the city or county misses the 60-day deadline?
Under AB 3182, which took effect in 2025, a complete ADU application that isn’t approved or denied within 60 days is deemed approved.
Can I submit ADU plans online in Santa Clarita?
Yes. The City of Santa Clarita accepts ADU plans through its eService portal, or you can submit two paper sets. In LA County areas, plans typically go through the county’s EPIC-LA system.
Does an ADU need a public hearing?
No. State law requires ministerial review for a compliant ADU, so there’s no public hearing in either the City of Santa Clarita or LA County.
Can I pull the ADU permit myself as an owner-builder?
Yes, California allows owner-builders. You then take responsibility for the permit, inspections, and anyone working on the job, including workers’ compensation obligations. Most homeowners have their licensed contractor pull the permit.
What if my ADU permit is denied?
True denials are uncommon, because state law limits the grounds for denying a compliant ADU. Most “rejections” are correction notices. If you get a denial that seems to conflict with state law, use the agency’s appeal process and consider contacting the California Department of Housing and Community Development (HCD). See why ADU permits get rejected.