ADU Regulations in Petaluma, California (2026)

Regulations at a glance

Local rules & notes

Useable Open Space Requirement: The city requires a minimum of 600 square feet of useable open space for the ADU project. Permeable Paving Mandate: A local Cal-Green Tier 1 requirement mandates that at least 20% of new parking or walking surfaces must be permeable. EV Ready Requirement: Petaluma Municipal Code requires the installation of a dedicated 208/240-volt branch circuit for future EV charging.

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

Frequently asked questions about ADU regulations in Petaluma

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

  In Petaluma, the maximum ADU size is typically 1000 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; Petaluma may follow state defaults or have local limits. Verify with Petaluma planning for your specific lot.

• What are the setback requirements for ADUs in Petaluma?

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

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

  In Petaluma, the maximum height for an ADU is generally 21 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 Petaluma or county planning for your zone.

• Is ADU approval ministerial in Petaluma?

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

• Are there parking requirements for ADUs in Petaluma?

  In Petaluma, 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 Petaluma planning for your address.