Accessory Structures in Alameda, CA (2026)
6 verified accessory structures rules for Alameda, California, sourced directly from the municipal code and official government pages.
Verified from official government sources
ADU Rules
Alameda caps detached accessory dwelling units at 1,200 square feet and 18 feet tall, with a bonus to 20 feet for a matching roof pitch. Detached ADUs need a 4-foot side and rear setback unless built in an existing structure's footprint.
Alameda ADU Size, Height and Setback Rules
Some RestrictionsAlameda, CA, Municipal Code Sec. 30-5.18.c.2, c.4.a, c.4.b(2) (Accessory Dwelling Units, Ord. No. 3184 N.S. as amended by Ord. No. 3333 N.S.)
2.Maximum Size: The size of an accessory dwelling unit shall not exceed one thousand two hundred (1,200) square feet. Nothing in this section shall be interpreted to prohibit at least an eight hundred (800) square foot accessory dwelling unit that is sixteen (16′) feet in height with four (4′) foot side and rear yard setbacks to be constructed in compliance with all other development standards....
ADU Impact Fees
Alameda exempts accessory dwelling units from its Improvement Tax under AMC Section 3-62 and bars treating an ADU as a new residential use for water or sewer connection fees and capacity charges, cutting standard project costs.
Alameda ADU Impact Fee Exemptions
Few RestrictionsAlameda, CA, Municipal Code Sec. 30-5.18(a)(4) and (j) (Accessory Dwelling Units, Ord. No. 3184 N.S. as amended by Ord. No. 3333 N.S.)
4.Not be considered a new residential use for the purposes of calculating connection fees or capacity charges for utilities, including water and sewer service....j.Accessory dwelling units shall be exempt from the Improvement Tax provisions in AMC Section 3-62, Improvement Tax.
ADU Owner Occupancy
Alameda requires the property owner to record a deed restriction before a junior accessory dwelling unit permit issues, promising owner-occupancy of either the primary home or the JADU, waived only for a public agency, land trust or housing organization owner.
Alameda Junior ADU Owner-Occupancy Rule
Some RestrictionsAlameda, CA, Municipal Code Sec. 30-5.18(c)(6)(h)(2) (Junior Accessory Dwelling Units, Ord. No. 3184 N.S. as amended by Ord. No. 3333 N.S.)
(h)Before issuing a building permit for a junior accessory dwelling unit, the property owner shall file with the county recorder a declaration or an agreement of restrictions, which has been approved by the City Attorney as to its form and content, containing a reference to the deed under which the property was acquired by the owner and stating that:...(2)The applicant shall be an owner-occupan...
ADU Rental Restrictions
Alameda bars selling or conveying an accessory dwelling unit apart from the primary home, except as state law allows, and requires any ADU rental to run longer than 30 days, ruling out short-term and vacation rentals of the unit.
Alameda ADU 30-Day Minimum Rental Rule
Some RestrictionsAlameda, CA, Municipal Code Sec. 30-5.18(e) (Accessory Dwelling Units, Rental and Sale Limitations, Ord. No. 3184 N.S. as amended by Ord. No. 3333 N.S.)
e.Rental and Sale Limitations. The accessory dwelling unit shall not be sold or otherwise conveyed separately from the primary dwelling except as allowed pursuant to Government Code Section 65852.26, and rental of an accessory dwelling unit shall be for a period longer than thirty (30) days.
Shed & Carport Rules
Alameda caps backyard sheds and other accessory buildings at one story and ten feet at the parapet under Municipal Code Section 30-5.7.f, with coverage limited to six hundred square feet or sixty percent of the required rear yard, whichever is greater, and a five-foot side setback for buildings within seventy-five feet of the front property line.
Alameda Accessory Building Size and Setback
Some RestrictionsAlameda, CA, Municipal Code Sec. 30-5.7.f (Accessory Buildings)
f.Accessory Buildings. Accessory buildings may be located within minimum required side and rear yards, and shall conform to the following:1.Height Limits. Accessory buildings shall not exceed one (1) story, and shall not exceed a height of ten (10′) feet at the top of a parapet or at the point where the side elevation intersects with the roof, with the following exceptions:(a)The height at the ...
Garage Conversions
Alameda lets an existing garage convert to an accessory dwelling unit with no added setback if it keeps the original footprint, but requires the garage door opening be rebuilt to match the exterior wall material, color and window trim of the building.
Alameda Garage-to-ADU Conversion Standards
Some RestrictionsAlameda, CA, Municipal Code Sec. 30-5.18(c)(4)(b)(1) and (c)(5)(c) (Accessory Dwelling Units, Ord. No. 3184 N.S. as amended by Ord. No. 3333 N.S.)
(b)Required Setbacks from Side and Rear Property Lines:(1)No setbacks shall be required for an existing accessory structure or a new structure constructed in the same location and to the same dimensions as an existing structure that is converted to an accessory dwelling unit. For purposes of this subsection, dimensions shall mean the exterior width, length, and height of the existing accessory ...
Looking for Alameda County county-wide rules?
County ordinances apply to unincorporated areas and may supplement Alameda city rules.
Accessory Structures in Alameda County →