Room Addition 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 →

Population: 12,513 Code: 2025 CRC Verified: 2026-05-22 1 local rules

When you need a Addition permit in San Marino

Required·Rule 1

Any habitable-space addition requires a building permit plus electrical and plumbing permits as applicable. Submit hard-copy plans to City Hall, 2200 Huntington Drive, (626) 300-0700. Strict zoning: FAR (Floor Area Ratio) limits apply; historic preservation review may apply; Mills Act contracts available for designated historic properties (additions are a primary trigger for historic review). Plans must address: 2025 Title 24 Part 6 energy compliance for CA Climate Zone 9, seismic (SDC D) lateral analysis near the Raymond and Sierra Madre faults, NFPA 13D fire sprinklers (CRC R313, sprinklers may extend to the addition depending on scope), CALGreen Tier 1 measures, mandatory solar PV trigger if creating new conditioned floor area. VHFHSZ may apply to specific hillside parcels per state mapping (verify via CAL FIRE map); on those parcels, Chapter 7A ignition-resistant exterior is required. Inspections Mon-Thu only (no Friday building inspections).

Typical Timelineabout 9 weeks
SourceCity of San Marino Building & Safety / 2025 CRC / Title 24 / CALGreen / Chapter 7A + SMCC Chapter 25 · view source

Room Addition Permit Costs: San Marino vs. Nearby

CityEstimated Fee
San Marino N/A
Los Angeles $1,000 – $20,000
Sacramento County $200 – $2,000
San Diego $850 – $17,000

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

Zoning

Room additions typically require zoning review for setbacks, height limits, and lot coverage. Your addition must comply with your zoning district's building envelope requirements.

HOA Communities

If you live in an HOA community: room additions almost always require HOA architectural review approval. HOAs may restrict the size, style, materials, and exterior appearance of additions to maintain neighborhood consistency.

Estimated Project Timeline in San Marino

Here's a typical timeline for a room addition project in San Marino, CA:

Week 1
Get quotes & finalize design
Contact licensed contractors, get 3+ quotes, finalize project scope and drawings (plan drawings required).
Week 2
Prepare permit documents
Contractor prepares site plan, construction drawings, and permit application. Gather required documents per your city's checklist.
Week 3
Submit permit application
Your contractor submits the application to San Marino's building department, apply online here.
Week 4-12
Plan review & approval
Typical processing time in San Marino: about 9 weeks. Plan review examiner checks drawings for code compliance.
Week 13+
Construction & inspections
Post the permit card on site. Work begins. Schedule inspections at required stages (varies by project). Final inspection required before closing the permit.

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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Building Department Contact

NameCity of San Marino Community Development Department, Building & Safety Division
Address2200 Huntington Drive, San Marino, CA 91108
HoursBuilding Division counter Mon-Thu 7:00 AM - 5:00 PM (payments by 4:00 PM), Fri 7:00 AM - 11:00 AM (payments by 10:00 AM). Planning counter Mon-Thu 7:00 AM - 12:00 PM. Building Inspector Mon-Thu 7:00 AM - 8:00 AM at (626) 300-0753.

Frequently Asked Questions

Contact San Marino's building department for current Room Addition permit fee information. Fees typically vary based on project scope and valuation.

It depends on the specifics of your project. Some smaller Room Addition 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 Room Addition 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 Room Addition Permits

Read our complete guide covering permit requirements, costs, common exemptions, and the application process.

Read Room Addition Guide →

Estimate your permit fees →

Disclaimer: This information was last verified on 2026-05-22. Building permit requirements may change. Zoning requirements (setbacks, lot coverage, height limits) are separate and vary by location. Always confirm with your local building and planning departments before starting your project. PermitMint provides general guidance, not legal advice.