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Santa Maria, CA Accessory Structures: ADU Rules (2026)

Some Restrictions

Compiled from the official code textEditor Martyn O'NeillLast verified September 2026

ADU rules in Santa Maria, CA, also called accessory dwelling unit regulations or granny flat ordinances, cover setbacks, owner-occupancy, parking, and permit requirements.

Key Facts

Detached ADU max size: 1,200 sq ft
Side/rear setback: 4 ft minimum
Parking near transit: Waived within 1/2 mile of public transit
Ministerial review: 60 days from complete application
JADU max size: 500 sq ft within primary residence

ADU Eligibility Quick-Check

An Accessory Dwelling Unit (ADU) is a smaller, independent living unit on the same lot as a single-family home: converted garages, detached cottages, basement or attic conversions, and attached additions all qualify. Most states have streamlined ADU permitting since 2020, but local rules still control size, height, and setback.

Is your lot zoned single-family or multi-family residential?
Does your lot have at least 1,200 sq ft of buildable space?
Is your existing home owner-occupied (in most states this is not required, but some require it for ADU permits)?
Will the ADU stay under your state's size cap (commonly 850-1,200 sq ft for detached)?
Can you provide one off-street parking space (waived in many states within 0.5 mi of transit)?

If you answered 'yes' to most of these, you likely qualify in California under recent ADU streamlining laws. The Santa Maria, CA rules below cover local size, height, and setback requirements.

Summary

Santa Maria permits one ADU and one JADU per single-family lot ministerially within 60 days; detached ADUs may be up to 1,200 sq ft with 4-foot side/rear setbacks, and parking is waived within 1/2 mile of transit.

Section 12-56.04. Development standards for ADUs. ... (d) Building site. (2) Unit Size. Floor Area. a. New Construction Attached and Detached ADUs. i. The floor area of an attached, new construction ADU shall not exceed 50% of the existing primary dwelling unit's living area, or 850 square feet (1,000 square feet for ADUs that provide more than one bedroom), whichever is greater. ii. The floor area of a detached, new construction ADU shall not exceed 1,200 square feet. ... (f) Setbacks. (1) No setback shall be required for an existing accessory structure that is converted to an ADU. (2) An ADU that is constructed above a garage shall be set back a minimum of four (4) feet from the side and rear lot lines and shall follow the setbacks set forth by the garage whenever possible. (3) Attached and Detached ADUs: The side yard and rear yard setbacks for new structures containing an ADU shall be no less than four (4) feet. ... (g) Parking. (1) Parking for ADUs shall be provided at a rate of one parking space per ADU or per bedroom, whichever is less. ... (3) Parking is not required in any of the following instances: a. The ADU is located within 1/2 mile walking distance of public transit. ... (4) Replacement Parking. When a garage, carport, or covered parking structure is demolished or converted in conjunction with the construction of an ADU, off-street parking space replacement shall not be required.

Source: Santa Maria ADU OrdinanceView official code

Full Breakdown

Chapter 12-56 of Title 12 of the Santa Maria Municipal Code (adopted by Ordinance No. 2017-21 and comprehensively amended by Ordinance No. 22 governing Accessory Dwelling Units (ADUs) and Junior Accessory Dwelling Units (JADUs). 04 sets development standards: a detached new-construction ADU may not exceed 1,200 square feet; an attached new-construction ADU is limited to 50% of the existing primary dwelling's living area or 850 square feet (1,000 sq ft if more than one bedroom), whichever is greater; side- and rear-yard setbacks must be at least four feet; and an ADU above a garage requires a four-foot side/rear setback.

Conversion of existing structures has no floor-area cap and no setback requirement. 04(g), parking is one space per ADU or per bedroom, whichever is less, and is waived entirely when the ADU is within 1/2 mile walking distance of public transit, located in a historic district, part of the existing primary residence, or near a car-share location; demolished garage parking does not need to be replaced. 06 requires ministerial approval within 60 days of a complete application.

Violations & Fines

ADUs built without a building permit or zoning certificate from the Community Development Director may not be rented, leased, or occupied as a separate dwelling, and under Section 12-56.09 unpermitted units must go through the conformance review (same standards as a newly proposed ADU) before they can be legalized.

Frequently Asked Questions

Do I need a discretionary permit for an ADU in Santa Maria?

No. Section 12-56.06 requires the Community Development Director to issue an ADU permit ministerially within 60 days of a complete application; no public hearing or discretionary review is allowed.

Can my ADU be sold separately from the main house?

No. Section 12-56.04(b)(1)(a) prohibits selling an ADU separately from the primary dwelling unit, and the same restriction applies to JADUs under Section 12-56.05(b)(1)(a).

Is owner occupancy required?

Owner occupancy is not required for an ADU but is required for a JADU under Section 12-56.05(b)(1)(c) - either the primary dwelling or the JADU must be the owner's permanent residence.

Sources & Official References

Other rules in Santa Maria

Shed & Carport RulesSome Restrictions ADU Owner OccupancySome Restrictions ADU Rental RestrictionsSome Restrictions ADU Impact FeesLight Restrictions Garage ConversionsSome Restrictions Parking Rules: Loading ZonesSome Restrictions Parking Rules: EV ChargingLight Restrictions Parking Rules: Curb Color RulesSome Restrictions Animal Ordinances: Veterinary Clinic ZoningSignificant Restrictions Landscaping Rules: Artificial TurfLight Restrictions Landscaping Rules: Native PlantsFew Restrictions

All Santa Maria rules

How Santa Maria compares: Easiest Cities to Build an ADU·California rules heatmap·Compare Santa Maria to another location·View the California accessory structures overview

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