ADU Regulations in Colusa, California (2026)

Regulations at a glance

Local rules & notes

Safe Harbor for ADU Projections: HCD allows jurisdictions to assume an average increase of five times the previous planning period construction trends for ADUs to account for new state laws removing barriers. Colusa County Exemption: Unincorporated parts of Colusa are exempt from the requirement to determine if sites were used in previous planning periods (Step 1 analysis). ADU Affordability Methodology: Jurisdictions can determine ADU affordability by surveying market rents, using regional studies, or comparing to comparable rental properties.

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

Frequently asked questions about ADU regulations in Colusa

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

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

• What are the setback requirements for ADUs in Colusa?

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

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

  In Colusa, 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 Colusa or county planning for your zone.

• Is ADU approval ministerial in Colusa?

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

• Are there parking requirements for ADUs in Colusa?

  In Colusa, 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 Colusa planning for your address.