ADU Builder in Antioch, CA
Antioch is the East Bay’s most affordable option for homeowners who want to tap into Bay Area rental demand without the land costs of Oakland, Concord, or Walnut Creek. A well-positioned ADU here rents to exactly that tenant: Bay Area workers who need more space than Oakland allows and are willing to make the commute.
Apex Homes builds ADUs throughout Antioch, managing zoning review, permit preparation, and full construction under one roof. A few of Antioch’s local rules differ meaningfully from other Bay Area cities, particularly around setbacks and ADU size — worth knowing before you choose a design.
ADU Regulations in Antioch
Antioch follows California’s state ADU law with local standards that are more restrictive than some neighboring cities in a few specific areas. The front setback and maximum size limits are the most important to understand before selecting a floor plan.
Single-family lots (R-1)
- One detached or attached ADU + one Junior ADU (JADU) per lot
- Size: maximum 1,000 sq ft for detached ADUs (lower than the 1,200 sq ft allowed in many California cities); JADUs up to 500 sq ft
- Front setback: minimum 30 ft from the front property line — significantly more restrictive than the 4 ft side/rear standard
- Street-facing setback: minimum 20 ft from any street-facing property line on corner lots
- Side and rear setbacks: 4 ft minimum
- Height: one story, maximum 16 ft
- Parking: one off-street space required per ADU
Multi-family lots (R-2+)
- Up to 2 detached or attached ADUs per lot
- Interior conversions of existing non-livable spaces (garages, storage) also permitted
- Same size, setback, and height standards apply
The 30 ft front setback and 1,000 sq ft cap are the rules most likely to affect your design options in Antioch. Apex Homes checks both against your specific lot before any plans are drawn.
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Build Your ADU in Antioch
Enter your address in ParcelZ to check ADU eligibility, usable backyard depth relative to the 30 ft front setback, and compatible floor plans. Free. No account needed.
The Antioch ADU Permitting Process
ADU permits are processed through the Antioch Building Division. Review typically takes two to four months from a complete submittal. Working with a pre-approved or pre-reviewed plan reduces the scope of city plan-check and can meaningfully shorten that window.
Free Feasibility Study
Apex starts with a full property check: zoning designation, lot depth relative to the 30 ft front setback, backyard usable area, parking space availability, and whether the primary home has fire sprinklers (which determines sprinkler requirements for the ADU). All of this shapes which designs and sizes are viable before a dollar is spent on drawings.
Select a Floor Plan
Choose from one of Apex’s three pre-reviewed designs, each sized within Antioch’s 1,000 sq ft cap. Every plan includes a complete permit package — site plan, floor plans, elevations, structural calculations, and Title 24 energy documentation.
Permit Submittal
Apex compiles and submits the full package to the Antioch Building Division. A complete, accurate application is the best way to minimize correction rounds and keep the review timeline predictable.
Building Division Review
The city reviews under California’s 60-day ministerial approval requirement. Apex monitors the review and responds directly to any plan-check comments.
Construction & Inspections
After permit issuance and fee payment, Apex manages the full build through foundation, framing, MEP rough-in, city inspections, and final certificate of occupancy.
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Pre-Approved ADU Plans in Antioch
Antioch is actively supporting ADU development and may provide pre-approved ADU plans to simplify permitting and reduce costs. These plans have already been reviewed for compliance with the city’s zoning and building standards, allowing homeowners to move forward with confidence and faster approvals.
To explore available pre-approved ADU options or find a design that best fits your lot, contact the Antioch Building and Safety Division or the Apex Homes team for expert guidance.
Does a plan fit your lot?
Run your Antioch address through ParcelZ to check setback constraints, buildable area, and plan compatibility. Free, no account needed.
Why Build an ADU in Antioch?
Antioch’s growing housing demand and affordable land make it a great location to build an ADU. Homeowners can earn steady rental income while significantly increasing property value and long-term equity.
ADUs in Antioch are also a smart way to create flexible living space for family members, whether for parents, adult children, or guests. The city’s clear ADU standards and straightforward permitting process make building accessible for most homeowners.
Apex Homes builds ADUs across Antioch, offering complete design and construction services. Book a free consultation with our team to discover how an ADU can add space and value to your property.
Have questions? Contact Apex Homes Today
We build ADUs throughout Antioch and understand the Building Division’s process, and what the East Bay rental market will support. Free consultation, no obligation.