ADU Regulations in Lancaster, California (2026)

Regulations at a glance

Local rules & notes

Multifamily Detached ADU Expansion (SB 1211): Effective Jan 1, 2025, up to eight detached ADUs are authorized on a lot with an existing multifamily dwelling, provided the number does not exceed the number of existing units. Pre-Approved ADU Plans Mandate (AB 1332): Local agencies are required to develop a program for the preapproval of ADU plans by January 1, 2025, and must approve/deny applications using these plans within 30 days. Unpermitted ADU Amnesty (AB 2533): Local agencies cannot deny permits for unpermitted ADUs built before Jan 1, 2020, unless there is a health/safety violation. They also cannot charge impact fees for these if the owner is low-income.

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

Frequently asked questions about ADU regulations in Lancaster

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

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

• What are the setback requirements for ADUs in Lancaster?

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

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

  In Lancaster, 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 Lancaster or county planning for your zone.

• Is ADU approval ministerial in Lancaster?

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

• Are there parking requirements for ADUs in Lancaster?

  In Lancaster, parking for ADUs is generally 1. California law often waives parking for ADUs within a half-mile of transit or in certain historic districts. Check with Lancaster planning for your address.