Alhambra, CA Accessory Structures: Garage Conversions (2026)

In the City of Alhambra, converting a garage into living space is generally accomplished through the accessory dwelling unit (ADU) or junior ADU (JADU) provisions of Zoning Code Section 23.22.040, which implement California Government Code 66310 et seq. Per City guidance, where an accessory structure or a portion of an existing residence is converted into an ADU, no additional parking space is required, and conversions within an existing structure require no new setback (subject to fire and safety code). JADUs must be created entirely within the walls of an existing or proposed single-family dwelling and are capped at 500 sq ft, with expansion limited to 150 sq ft for ingress/egress only. A converted unit must include independent exterior access separate from the main residence and contain a kitchen or kitchenette and a bathroom with a shower or bathtub; JADUs may share a bathroom and have a more limited kitchen. Converted ADUs may not be used as short-term rentals (Chapter 5.92). Because the space changes from non-habitable to habitable, the work triggers building-permit plan check for items such as insulation, egress, smoke/CO detectors, and electrical. Owners should verify whether removing required covered parking is permitted and whether replacement parking applies; under state law, no replacement parking is required when a garage is converted to an ADU.