County Building Permits
San Mateo County, CA - 2026 Building Permit Guide
How to apply for a building permit in unincorporated San Mateo County, California. Permit authority, application steps, fees, and inspection requirements.
Permit Authority
The Planning and Building Department issues permits for planning and building projects in unincorporated San Mateo County; Division VII Building Regulations apply in unincorporated areas. Source: https://www.smcgov.org/planning/apply-permit ; https://www.smcgov.org/planning/county-division-vii-building-regulations
- Department
- San Mateo County Planning and Building Department
- Address
- 455 County Center, 2nd Floor, Redwood City, CA 94063
- Phone
- Building Counter (650) 599-7310; Building Inspections (650) 599-7311
- Website
- https://www.smcgov.org/planning
Online Permit Portal
Platform: Accela Citizen Access (county permit system) • Account required: Yes • Submission: Online only
Additional resources:
Application Process
- Apply for building permit online.
- County staff checks for complete submittal and initial fees (typically within 5 days for building permits).
- Referral and plan check by required agencies (Planning, Public Works, Fire, Civil/Drainage, Geotechnical) with a typical 30-day agency review target.
- Resubmittal and resubmission if comments are issued.
- Permit issuance after required plan checks pass and final fees are paid.
- Inspections scheduled; final inspection at completion before occupancy/use of the permitted area.
- Scope changes may trigger a revisions cycle.
Typical processing time: initial completeness review ~5 days; review agencies generally complete plan checks within 30 days for building permits.
General Requirements
A permit is needed when a building/structure will be erected, constructed, enlarged, altered, repaired, moved, improved, removed, converted, or demolished.
Required Documents
- Plans are submitted online in PDF and include plot, foundation, floor, elevation, and detail sheets with minimum scales, property identification, surveys if required, energy/fire/engineering information, and code-specified technical details.
- Permit validity
- New residences/additions are valid for 1 year and may be renewed once for a second year without extra fee; many smaller permits are also valid for 1 year to start construction. A progress inspection is required at least every 180 days and permits expire if extensions are not requested before expiry.
- Building code
- The County adopts and enforces IBC/California Title 24 family codes (2022 editions at ordinance level), the 2022 California Energy Code/Green Building Code and local amendments in Division VII for unincorporated areas.
- Owner-builder
- Workers’ Compensation coverage must be provided each time a permit is applied for. If claiming an exemption and hiring a contractor, owner-builders must provide contractor name, license number, and mailing address.
- Contractor requirements
- If a licensed-contractor exemption is used, contractor license information is required. Architect/engineer identification/license must be shown on plans where design sheets are required by permit type.
Fees
- Minimum permit fee
- $191 (residential), $381 (commercial) per current Building Service Fee Schedule.
- Plan check fee
- 65% of the calculated permit fee is required before plan review begins. Additional plan-check charges may apply on resubmittal rounds.
- Permit fee formula
- Sliding schedule based on review type and project characteristics (Easy/Moderate/Full Review categories), plus square-footage and valuation-based formulas depending on permit type.
- Reinspection fee
- Special inspection charges apply to special inspections and reinspections; listed examples include $191 charges in the fee schedule.
- Payment note
- Pay online (card or bank, fees may apply), or by mail/check to the County with permit/record number; also available at county office during business hours.
Fees change. Verify current amounts at the official fee schedule.
Work That Does NOT Require a Permit
Contact the San Mateo County Planning and Building Department to confirm whether your project requires a permit before starting work.
Inspections
How to Schedule
- Accela Citizen Access (county permit system) (online)
- (650) 599-7311 (phone)
- Time windows
- Inspections are generally scheduled between 8:00 AM and 3:30 PM; 3-hour estimated time windows are published online on the day of inspection.
Typical inspection sequence: initial inspections by trade phase, progress inspections during active work, and a final inspection prior to occupancy/use.
Additional Resources
- Building code: The County adopts and enforces IBC/California Title 24 family codes (2022 editions at ordinance level), the 2022 California Energy Code/Green Building Code and local amendments in Division VII for unincorporated areas.
- Zoning information: View zoning info
- Building Permit Fees
- Building Permit Requirements
- Apply Permit
- Schedule Inspection
- County Division Vii Building Regulations
- License lookup guide: California Contractor License Requirements
- Contract template: California Homeowner-Contractor Agreement
- California hub: California Contractor License & Permit Hub
Information on this page was last verified: March 2026. Permit rules and fees change — confirm current requirements directly with the San Mateo County Planning and Building Department before applying.
Frequently Asked Questions
San Mateo County Building Permit FAQ
- Do I need a building permit in unincorporated San Mateo County, CA?
- A permit is needed when a building/structure will be erected, constructed, enlarged, altered, repaired, moved, improved, removed, converted, or demolished.
- How much does a building permit cost in unincorporated San Mateo County, CA?
- The minimum permit fee is $191 (residential), $381 (commercial) per current Building Service Fee Schedule.. Fees are calculated as: Sliding schedule based on review type and project characteristics (Easy/Moderate/Full Review categories), plus square-footage and valuation-based formulas depending on permit type.. Plan check fee: 65% of the calculated permit fee is required before plan review begins. Additional plan-check charges may apply on resubmittal rounds..
- How do I apply for a building permit in unincorporated San Mateo County, CA?
- 1. Apply for building permit online. 2. County staff checks for complete submittal and initial fees (typically within 5 days for building permits). 3. Referral and plan check by required agencies (Planning, Public Works, Fire, Civil/Drainage, Geotechnical) with a typical 30-day agency review target. 4. Resubmittal and resubmission if comments are issued. 5. Permit issuance after required plan checks pass and final fees are paid. 6. Inspections scheduled; final inspection at completion before occupancy/use of the permitted area. 7. Scope changes may trigger a revisions cycle.
- How long does it take to get a building permit in unincorporated San Mateo County, CA?
- Typical processing time is initial completeness review ~5 days; review agencies generally complete plan checks within 30 days for building permits..
- How do I schedule a building inspection in unincorporated San Mateo County, CA?
- Inspections can be scheduled via: Accela Citizen Access (county permit system), (650) 599-7311.
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