Alameda County, California Building Permit Guide

Building permits for unincorporated Alameda County are issued by the Building Inspection Department of the Alameda County Public Works Agency (ACPWA). Apart from flood control, ACPWA “primarily serves the unincorporated areas of Alameda County.” The unincorporated communities include Ashland, Castro Valley, Cherryland, Fairview, Hayward Acres, San Lorenzo, Sunol and rural east county communities outside the cities of Livermore, Dublin and Pleasanton.

This guide covers the County’s Building Inspection Department. The fee schedule the County links (effective July 1, 2024) and its inspection-request brochure are both filed under “Archived” file names, so their figures may be out of date; confirm with the Department.

What requires a building permit in Alameda County?

The County’s Q&A on permit exemptions says window replacement always needs a building permit, because of the California Energy Code. Trellises, arbors, patio covers and similar sunshade structures at single-family homes may be exempt if each is no more than 120 square feet and averages no more than 10 ft high.

Even when work is exempt from a building permit, approval may still be needed from the Planning Department, Environmental Health, the Fire Department or Road Encroachment, and signs need Planning Department approval before installation.

Public Works issues separate permits for encroachment (work in County roads, sidewalks and rights-of-way), drilling and wells, tree removal in unincorporated areas, grading, and stormwater and watercourse work. Septic and other onsite wastewater systems are permitted by Environmental Health’s Onsite Wastewater Systems (OWS) Program.

California builds on one statewide code, Title 24, whose 2025 edition took effect on 1 January 2026; the editions in effect when the application is submitted apply, and cities and counties may adopt local amendments only with findings filed with the state (new residential amendments are largely frozen until June 2031). Title 24 and local amendments

Who handles permitting in Alameda County?

How to get a building permit in Alameda County

A building permit carries a validity period and can expire if work does not start or stalls between inspections; confirm the expiry with the County Building Inspection Department on phased or delayed work. Permit validity in California

Alameda County permit costs and fees

From the Building Inspection Department Service Fee Schedule (Schedule A, effective July 1, 2024; filed by the County as an archived document):

• A $140.00 minimum fee or hourly rate applies to any plan review, permit or inspection service.
• Building permit: $140.00 for $1.00 to $1,000.00 of valuation; for $10,001.00 to $50,000.00, $381.46 for the first $10,000 plus $8.88 for each additional $1,000.00.
• Building plan review: 80% of the building permit fee, $140.00 minimum. Permit processing fee: $20.00 per single permit, $30.00 per combo permit.
• Residential solar or other renewable energy system under 35 Kva with no plan review: $280.00 for the first system, $140.00 for each additional one.
• Re-inspections: $140.00 per hour; inspections outside normal business hours: $210.00 per hour, two hours minimum.

Inspections in Alameda County

Inspections can be scheduled in the permit portal or phoned in 24 hours a day, seven days a week on the automated Inspection Request Line, (510) 670-5434; requests must be received before 12 A.M. on the day you want the inspection. Have the permit number and the Inspection Type Code from the job card. These phone details come from the County’s archived inspection brochure, so confirm them with the Department. The County also posts a daily inspection route sheet.

Official Alameda County permitting resources

These are the primary sources behind this guide. Codes, fee schedules and procedures change — confirm the position for your filing date.

• ACPWA permits
• About the Alameda County Public Works Agency
• Submittal and plan review timelines (PDF)
• Fee Schedule A, July 1, 2024 (PDF)
• Permit exemption Q&A (PDF)
• Alameda County Planning Department
• Onsite Wastewater System Program

Frequently asked questions

Does window replacement need a permit in unincorporated Alameda County?

Yes. The County says a building permit is always required for window replacement, because of the California Energy Code.

How long does County plan review take for an ADU?

The County publishes 5 business days for intake, 20 for the first review and 10 for later reviews, for projects with Planning/Zoning approval.

Where do I apply?

Through the County’s online permit portal, acpermit.acgov.org, which is also used to schedule inspections and check permit status.

Simplify Alameda County permitting with Alliance Permitting

• Confirm which office has the parcel and which other agencies must sign off before the building permit
• Prepare the application and plans in the format the local portal accepts
• Track plan review, pay fees and schedule inspections against each office’s cut-off

Alliance Permitting is a permit documentation and submission company in California. We prepare your paperwork, file it correctly and coordinate with the permitting authority through issuance. We are not a contractor and we do not perform licensed plan review or inspections; that work stays with your licensed team and the jurisdiction.

This guide is provided by Alliance Permitting for general information about Alameda County permitting. Requirements, fees, and procedures change; confirm details with the permitting authority before relying on them.