ADU Regulations in Martinez, California (2026)

Regulations at a glance

Local rules & notes

Illegal Visibility Standards: The city attempted to ban exterior staircases visible from the public right-of-way, which HCD ruled as an illegal subjective standard. Unit Combination Allowance: Martinez must allow a homeowner to create one converted ADU, one detached new construction ADU, and one JADU on a single-family lot. Front Setback Preemption: Local front setback standards cannot preclude the construction of an 800 sq ft ADU with 4-foot side/rear setbacks.

For the official ordinance and latest updates, check your city or county planning department.

Frequently asked questions about ADU regulations in Martinez

• What is the maximum ADU size in Martinez, California?

  In Martinez, 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; Martinez may follow state defaults or have local limits. Verify with Martinez planning for your specific lot.

• What are the setback requirements for ADUs in Martinez?

  In Martinez, 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 Martinez planning for overlay zones or design standards that could affect your site.

• What is the maximum height for an ADU in Martinez?

  In Martinez, 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 Martinez or county planning for your zone.

• Is ADU approval ministerial in Martinez?

  In Martinez, 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; Martinez planning can confirm the exact process.

• Are there parking requirements for ADUs in Martinez?

  In Martinez, parking for ADUs is generally true. California law often waives parking for ADUs within a half-mile of transit or in certain historic districts. Check with Martinez planning for your address.