ADU Permit Requirements in San Marino, CA
San Marino is a small affluent residential city in western LA County; ZIP 91108 is wholly within incorporated limits. The City of San Marino Community Development Department (Building & Safety Division) at City Hall (2200 Huntington Drive) handles all permits; LA County DPW does NOT serve San Marino. California 2025 Title 24 framework effective 2026-01-01: 2025 CBC, CRC, CEC, CMC, CPC, California Energy Code, CALGreen with CA amendments, plus San Marino City Code Chapter 25 local amendments. Online portal is CommunityCore: roofing, electrical, and plumbing permits can be issued online; remodels, additions, and other major work require hard-copy submission. Solar applications use SolarAPP+. Inspections Mon-Thu only (no Friday). Over-the-counter VCA plan check available Tuesdays 10-11 AM (first 5 sign-ins). 3 percent credit card processing fee effective 2025-07-13. Fire/EMS by City of San Marino Fire Department (NOT LA County Fire): (626) 300-0735, fire@sanmarinoca.gov. Strict zoning: FAR limits, historic preservation, Mills Act contracts available. Hillside parcels may fall within VHFHSZ per state mapping. CSLB licensing required for projects over $500. Mandatory solar PV on new homes per CA Energy Code 150.1(c)14.
By Joey, Founder · Last verified May 22, 2026 · How we research →
When you need a ADU permit in San Marino
Accessory dwelling units (ADUs) and junior ADUs (JADUs) are streamlined under California state ADU law (AB 68, AB 881, AB 671, SB 13). The City of San Marino must approve compliant ADUs within 60 days, with no minimum lot size, 4-foot setbacks, parking waivers within 1/2 mile of transit, and reduced impact fees (waived for ADUs under 750 sq ft). ADUs follow standard CRC + Title 24 + CALGreen + fire sprinklers (CRC R313, with some exceptions for small ADUs). VHFHSZ may apply to specific hillside parcels per state mapping (verify via CAL FIRE map); on those parcels, Chapter 7A applies. Hillside parcels may require additional grading and geology review. Submit hard-copy plans to City Hall, 2200 Huntington Drive, (626) 300-0700. Inspections Mon-Thu only (no Friday building inspections).
ADU Permit Costs: San Marino vs. Nearby
| City | Estimated Fee |
|---|---|
| San Marino | N/A |
| Los Angeles | $750 – $7,500 |
| Sacramento County | $750 – $7,500 |
| San Diego | $750 – $7,500 |
Fees shown are estimates based on local building code data. Actual fees may vary based on project scope and valuation. See all San Marino permit costs →
Zoning & HOA Considerations
ADU regulations vary dramatically by state and city. Many states (CA, OR, WA) have preemption laws that override local zoning restrictions. Check both state law and local zoning before designing.
If you live in an HOA community: hOAs have traditionally restricted ADUs, but state preemption laws in CA, OR, WA, and other states now limit HOA authority over ADUs. Check your state's ADU laws, your HOA may not be able to block construction even if CC&Rs appear to prohibit it.
Estimated Project Timeline in San Marino
Here's a typical timeline for a adu project in San Marino, CA:
Timeline is based on San Marino's typical about 9 weeks permit processing time. Actual timelines vary by project complexity, completeness of application, and current department workload.
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Frequently Asked Questions
Contact San Marino's building department for current ADU permit fee information. Fees typically vary based on project scope and valuation.
It depends on the specifics of your project. Some smaller ADU projects may be exempt from permit requirements, while larger ones typically require a permit. Use our free lookup tool to check your specific situation.
Working without a required permit in San Marino can result in fines, stop-work orders, being required to remove completed work, and complications when selling your home. It's always best to check first.
Typical approval time for ADU permits in San Marino is about 9 weeks. More complex projects may take longer if plan review is required.
If you live in an HOA community, you may need architectural review approval in addition to a building permit. HOA rules and city building codes are separate, you may need to satisfy both. Review your CC&Rs and submit to your HOA's architectural review committee before starting work.
Learn More About ADU Permits
Read our complete guide covering permit requirements, costs, common exemptions, and the application process.
Read ADU Guide →