GetYourPermit

ADU permit guide for Sebastopol, California

Sonoma County, CaliforniaReviewed August 29, 2026

Building & Safety Department reviews local ADU permits through the City Online Portal System. Use this page to plan the local process and the fee questions to verify before you submit.

Prepared by GetYourPermit editorial teamReport an error

Permit fee planning by size

GetYourPermit research · 2 published reference lines

ADU sizeResearched range
600 sq ft$4,600 – $12,300
800 sq ftimpact-fee band$7,400 – $20,300
1,000 sq ft$9,700 – $26,400
1,200 sq ft$11,600 – $31,300
Build a Sebastopol permit reportDetailed fee breakdown

Getting the permit

Department
Building & Safety Department
Where to apply
City Online Portal System
View the full 8-step permit process

Reference pages to verify