ADU permit process in Hillsborough, 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
Submit ADU packet to Planning ADU Specialist for initial review
Prepare ADU Application and City-listed architectural/site materials Contact Town ADU Specialist for initial review Planning-determined review/approval pathway
- 2
Address Planning comments or pursue required Planning approval path
Respond to Planning conditions or comments For Planning Permit/Exception path, obtain required Planning approval Planning authorization memo or Planning approval
- 3
Register for eTRAKiT and submit Building Permit materials after Planning authorization
Register with Town and obtain eTRAKiT credentials Submit approved-consistent construction drawings, Building application and fees Electronic Building Permit application
- 4
Pay fees and receive issued electronic permit
Pay applicable permit payment Receive issued permit through eTRAKiT Electronically issued permit
- 5
Request required Town inspections and keep approved plans on site
Request inspections at least 48 hours in advance Keep approved stamped plans and permit card at site Required inspection outcome
What you need to submit
- Architectural plans, parcel information and fire-access site plan
- Accessory Dwelling Unit (ADU) Review Application
- Construction notice and affidavit of mailing — only in some cases
Pre-approved ADU plans
Use Hillsborough’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 Hillsborough 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 reviewed current official schedule presents FY 2026-27 Building Division and Planning Division fees, including ADU flat permit rows, valuation-based permit rows, plan-check percentages, and City fee layers.
Accessed August 28, 2026
The Town states that its Master Fee Schedule is updated annually and submitted with the annual budget for City Council approval; it links the reviewed current schedule.
Accessed August 28, 2026
Accessed August 28, 2026
The official Town Building Division page identifies the department responsible for building permits and the permit-inquiry contact route.
Accessed August 28, 2026