Clayton, CA Building Permit Guide

Permit Authority

Clayton contracts with Contra Costa County for building permit and inspection services. Clayton handles preliminary zoning/local review and contractor business-license verification; Contra Costa County performs plan check, issues building permits, and conducts inspections for projects in Clayton.

Department

City of Clayton Community Development Department; Contra Costa County Department of Conservation and Development, Building Inspection Division

Address

Clayton City Hall, 6000 Heritage Trail, Clayton, CA 94517; Contra Costa County Application and Permit Center, 30 Muir Road, Martinez, CA 94553

Phone

City of Clayton Community Development (925) 673-7343; City main line (925) 673-7300; Contra Costa County Building and Planning (925) 655-2700

Email

No general Clayton building email is prominently published on the Clayton building page , county building permit staff email is referenced on county permit-help pages but is obfuscated by the website's email-protection service

Website

https://claytonca.gov/community-development/building/ ; https://www.contracosta.ca.gov/7863/Building-or-Grading-Permit-Overview

Online Permit Portal

Application Process

1. Contact Clayton Community Development early to confirm zoning and local requirements before preparing the full package.
2. Prepare plans and supporting documents. Clayton says applications generally need construction plans, structural engineering, energy design calculations, and soils reports as applicable; the county also expects plan sets and often architectural, structural, electrical, mechanical, plumbing, and Title 24 documents depending on scope.
3. For most Clayton projects, submit the completed building permit application and plan set to Clayton at City Hall or by email. Clayton reviews for zoning compliance, engineering review if required, stormwater permit requirements, construction and demolition debris recycling requirements, and verification of a current Clayton business license for contractors.
4. If the project affects sanitary sewer service or otherwise needs outside utility review, obtain any required City of Concord review and sewer-related approvals.
5. Submit to Contra Costa County for construction plan check, fee payment, permit issuance, and inspections. For permit types eligible for county ePermits direct processing, Clayton notes residential rooftop solar, plumbing, and mechanical permits may proceed through the county system after city-side requirements are satisfied.
6. County initial completeness review takes about 4 to 5 business days. Total issuance time depends on project scope, completeness, and whether plan corrections are required; the county does not publish a single standard turnaround for all building permits.
7. After issuance, schedule required inspections with Contra Costa County and obtain final approval before closing out the permit.

Typical processing time: County initial review about 4 to 5 business days; full plan review and issuance timeline varies by scope and completeness.

Source: City of Clayton Community Development Department; Contra Costa County Department of Conservation and Development, Building Inspection Division

General Requirements

Clayton states most building, demolition, and home improvement projects require a permit, including pools, spas, accessory structures, additions and alterations, decks, gazebos, arbors, kitchen and bath remodels, patios, doors and windows, electrical work, reroofs, new residential and commercial buildings, signs, tenant improvements, and replacement water heaters, furnaces, and air conditioners. County guidance also says almost all projects involving new structures, demolitions, additions, remodels, utilities, decks, garages, pools, ADUs, solar, storage systems, and generators require plans and permit review.

Required Documents

• Typically includes a completed application, plan set, project scope, property address, current code cycle on plans, structural details, Title 24 energy documents as applicable, and supporting reports such as soils/geotechnical, drainage, CalGreen debris compliance, and other agency approvals when triggered.

Permit validity

County plan-check applications are deemed abandoned after 180 days if not pursued in good faith or issued. Issued building permits expire 365 days from issue if no required inspection is approved, or if 365 days pass between approved inspections. Extension requests must be submitted 30 days before expiration.

Building code

Contra Costa County's current building code summary, updated January 2, 2026, lists the 2025 California Building Standards Code set as current, effective January 1, 2026, plus Contra Costa County Code Title VII and applicable city ordinances depending on the city where the property is located. Clayton's building page confirms county enforcement in Clayton for the California Building, Electrical, Mechanical, Plumbing, and Green Building Standards Codes.

Owner-builder

Owner-builders may apply for permits on their own property and may need proof of ownership. If an authorized agent applies for an owner-builder permit, the county requires an Authorization of Agent form before issuance.

Contractor requirements

County permits can be issued to licensed contractors, property owners, or authorized agents. Contractors must connect their CSLB license to the county ePermits account. For Clayton projects, contractors also need a current Clayton business license before the county will issue the permit. For commercial jobs other than single-family residences, the county states permits will only be issued to the licensed contractor doing the work.

Fees

Minimum permit fee

The county fee schedule is valuation-based. For building permits, the construction inspection schedule starts at $75 for projects up to $2,000 improvement value, and plan review starts at $49 for projects up to $2,000 improvement value. Some trade permits also expressly state a $75 minimum.

Plan check fee

County fee schedule Section S-001A Plan Review is valuation-based, starting at $49 plus $8.94 per additional $1,000 or fraction above $2,000, with graduated tiers thereafter.

Permit fee formula

Valuation-based for core building permit review, processing, plan review, inspection, energy compliance, and access compliance, with separate flat or hourly fees for some specialized services and revisions.

Reinspection fee

County fee schedule lists reinspection charges of $150 per trip in cited situations; the SolarAPP+ page also warns of a $150 reinspection fee if required inspection documents are missing or the system is not installed per plans.

Penalty (no permit)

Expired permit renewal fees also apply.

Payment note

Online payments go through the county ePermits Center. The county's current permit payments page says credit cards incur a 2.75% convenience fee with a $1 minimum, and e-checks incur a $2.50 convenience fee. The county states the convenience fee is charged by its third-party processor and appears as a separate charge.

Fees change. Verify current amounts at the official fee schedule.

Work That Does NOT Require a Permit

• One-story detached accessory structures not exceeding 120 square feet, subject to planning/sanitary/environmental caveats
• Fences not over 7 feet high
• Retaining walls not more than 3 feet high, measured from top of footing to top of wall, if not supporting surcharge or excessive slope conditions
• Ordinary finish work such as painting, papering, tiling, carpeting, cabinets, countertops, and similar work
• Temporary motion picture, television, and theater stage sets and scenery
• Certain above-ground prefabricated pools accessory to Group R-3 occupancy that are less than 24 inches deep and not greater than 5,000 gallons
• Swings and other playground equipment accessory to detached one- and two-family dwellings
• Certain window awnings in Group R-3 and U occupancies
• Nonfixed and movable fixtures, cases, racks, counters, and partitions not over 5 feet 9 inches high
• Detached decks for R-3 and U occupancies not exceeding 200 square feet, not more than 30 inches above grade, not attached to the dwelling, and not serving the required exit door

Important: Exemptions do not override zoning, floodplain, stormwater, environmental health, or other agency approvals. Electrical, plumbing, and mechanical work can still require permits even if the structure itself is otherwise exempt.

Inspections

How to Schedule

• (925) 646-4108 (phone)
• https://epermits.cccounty.us (online)
• https://aca-prod.accela.com/CCC (online)

Scheduling deadline

Same-day inspection requests by phone are accepted until 5:30 AM Monday through Friday.

Inspection hours

Same-day inspection requests by phone are accepted until 5:30 AM Monday through Friday. The county posts the current business day's inspection schedule after 8:45 AM, with 3-hour inspection windows. Online cancellations and reschedules are allowed before 6:00 AM on the day of inspection.

Time windows

Same-day inspection requests by phone are accepted until 5:30 AM Monday through Friday. The county posts the current business day's inspection schedule after 8:45 AM, with 3-hour inspection windows. Online cancellations and reschedules are allowed before 6:00 AM on the day of inspection.

Typical inspection sequence: Typical sequence depends on project scope. County inspection references include foundation inspections and final inspection, and projects proceed through the required trade/building inspections shown on the permit record before final approval. For qualifying SolarAPP+ permits, the county specifically directs scheduling the `120 Building-Final` inspection. Reinspection note: To avoid reinspection fees, the county requires the permit, reviewed/stamped plans, site access, corrected prior deficiencies, work readiness, and an adult representative onsite. Reinspection fees are published at $150 in the county fee materials and SolarAPP+ guidance.

Additional Resources

• Building code: Contra Costa County's current building code summary, updated January 2, 2026, lists the 2025 California Building Standards Code set as current, effective January 1, 2026, plus Contra Costa County Code Title VII and applicable city ordinances depending on the city where the property is located. Clayton's building page confirms county enforcement in Clayton for the California Building, Electrical, Mechanical, Plumbing, and Green Building Standards Codes.
• Zoning information: View zoning info
• https://claytonca.gov/community-development/permit-information/
• https://claytonca.gov/community-development/building/construction-demolition/
• https://www.contracosta.ca.gov/4777/Inspections
• https://www.contracosta.ca.gov/4748/Building-Code-and-Ordinances
• https://www.contracosta.ca.gov/4712/Contact-Location-Hours
• License lookup guide: California Contractor License Requirements
• Contract template: California Homeowner-Contractor Agreement

Other cities in Contra Costa County