ADU Regulations in Hercules, California (2026)
Summary from local ordinance data. Verify with city planning for your specific lot.
Regulations at a glance
| Rule | Value |
|---|---|
| Max ADU Size | 1200 sq ft |
| Side Setback | 4 ft |
| Rear Setback | 4 ft |
| Max Height | 16 ft |
| Approval Type | Ministerial (by-right) per Gov Code §65852.2 |
| Parking Requirements | Often waived per state law; check local ordinance |
Local rules & notes
Incorrect ADU/JADU Limitation: The City's ordinance incorrectly limited lots to having either one ADU *or* one JADU. HCD requires the City to change this to allow *both* one ADU *and* one JADU on lots with a single-family dwelling.
For the official ordinance and latest updates, check your city or county planning department.
Frequently asked questions about ADU regulations in Hercules
What is the maximum ADU size in Hercules, California?
In Hercules, the maximum ADU size is typically 1200 square feet, depending on whether the unit is attached or detached. California state law allows up to 1,200 sq ft for detached ADUs and 800 sq ft for attached in many jurisdictions; Hercules may follow state defaults or have local limits. Verify with Hercules planning for your specific lot.
What are the setback requirements for ADUs in Hercules?
In Hercules, typical setback requirements are 4 feet from the side property line and 4 feet from the rear. These may be reduced to 4 feet under California Government Code § 65852.2 where applicable. Check with Hercules planning for overlay zones or design standards that could affect your site.
What is the maximum height for an ADU in Hercules?
In Hercules, the maximum height for an ADU is generally 16 feet. State law often allows up to 16 feet for detached ADUs and up to 25 feet when within 4 feet of the property line in some cases. Confirm with Hercules or county planning for your zone.
Is ADU approval ministerial in Hercules?
In Hercules, ADU approval is typically Ministerial (by-right) per Gov Code §65852.2. Ministerial (by-right) review means the city must approve qualifying applications without discretionary review, per California Gov Code § 65852.2. Your project must still meet objective standards; Hercules planning can confirm the exact process.
Are there parking requirements for ADUs in Hercules?
In Hercules, parking for ADUs is generally Often waived per state law; check local ordinance. California law often waives parking for ADUs within a half-mile of transit or in certain historic districts. Check with Hercules planning for your address.
Check if your specific address qualifies
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