ADU permit process in Sonoma, California
Last verified August 29, 2026
Prepared by GetYourPermit editorial teamReport an error
This guide includes the portions of the City permit process that passed our evidence review. Confirm project-specific requirements with the City before submitting.
Where to apply
- Department
- Building Division
- Permit portal
- City Online Portal System
Step by step
- 1
Confirm parcel feasibility and current ADU rules
Use the City ADU reference page Contact Planning for parcel-specific zoning questions Contact Building for code/submittal questions Current parcel-specific permit and submittal direction
- 2
Prepare and submit the Building Permit application and plans
Select the Building Permit record type Upload plans and required supporting materials Provide site-specific supplements for a pre-reviewed plan Pay the initial/required plan-review fee Submitted Building Permit application
- 3
City intake and completeness screening
Respond if City requests missing intake material Application routed for review or intake deficiency notice
- 4
Building plan check and Planning compliance review
Monitor City requests Coordinate conditional Public Works, Fire or other review when directed Approvals, conditions or review comments
- 5
Resolve comments and resubmit when required
Revise the plan package Address all City and applicable agency comments Use the City-directed resubmittal channel Corrected plan package returned for review
- 6
Complete plan approvals and applicable outside clearances
Resolve remaining conditions Obtain any required agency approvals Permit ready for remaining fees/issuance
- 7
Pay required fees and receive the issued Building Permit
Pay required permit fees Receive and retain issued permit documents Issued Building Permit and approved plans
- 8
Construct to the issued plans
Keep issued documents available Complete work in approved sequence Do not conceal work before required inspections Work ready for phased inspection
- 9
Request and pass required phased inspections
Request Building inspections by phone or Permit Center Use separate Planning/Public Works/Fire channels when applicable Keep work exposed and provide required professional reports Inspection approvals or correction direction
- 10
Complete all work, applicable agency sign-offs and Building final
Complete all required inspections Obtain applicable agency signatures Request Building final after work is complete Building final approval or remaining correction requirements
- 11
Confirm permit closure and occupancy authorization
Follow the issued permit and City final instructions Do not assume occupancy authorization from a scheduling confirmation or one departmental inspection City-confirmed permit close-out and any applicable occupancy document
What you need to submit
- Building Permit application
- Construction drawings and supporting calculations/reports
- Site-specific plan, engineering and soils supplements for a City pre-reviewed design — only in some cases
- Applicable agency sign-off sheet and final approvals — only in some cases
Pre-approved ADU plans
Use Sonoma’s official page to confirm which designs, site conditions, and supplemental documents qualify. Plan-check timing still depends on the project and city review.
View pre-approved plansProject-specific next step
Build your Sonoma permit report
Choose your ADU type and size to bring the City process, researched permit fees, and early construction budget into one planning report.
Sources for this guide
Additional city reference pages
The live City page identifies the current 2023 Building fee schedule and expressly announces that a replacement takes effect September 1, 2026.
Accessed August 28, 2026
The current-until-September-1 City-hosted schedule gives the valuation table, permit-processing and plan-check fees.
Accessed August 28, 2026
The live City page confirms the ADU route and identifies the City ADU regulations and Planning Department contact.
Accessed August 28, 2026