South Pasadena ADU: Regulations, Costs & Permits

• Unit count: one attached or detached ADU, one JADU, and a conversion of an existing structure, so up to four homes on a single-family lot counting the main house.
• Attached ADUs: 150 sq ft minimum, up to 850 sq ft with one bedroom or 1,000 sq ft with two or more.
• Detached ADUs: 150 sq ft minimum, up to 1,200 sq ft. Up to 800 sq ft of any ADU can exceed the lot's FAR and lot coverage limits.
• Conversions: the existing structure plus up to 150 sq ft for access, or expanded up to 1,200 sq ft total.
• JADUs: up to 500 sq ft inside the house, with an efficiency kitchen and its own outdoor entrance. The owner must live in the house or the JADU.

• One story: 16 ft to the top of the roof or parapet, or 18 ft (plus 2 ft for roof pitch) for a detached ADU near major transit.
• Two stories: 18 ft with a flat roof plus a 1 ft parapet, or 22 ft with a pitched roof. Never more than two stories. Attached ADUs can reach 25 ft or the zone limit.
• Setbacks: 4 ft side and rear for new construction, plus the zone's front setback. Conversions need no setback, and a conversion with a tight side setback can extend that wall 10 ft if it stays 3 ft from the side line.
• Separation: detached ADUs over 800 sq ft need 10 ft from other buildings.

• Privacy on second floors: within 6 ft of a neighbor's line, windows below 5 ft above the floor must be fixed and obscured. Balconies face into your lot, and the second floor steps back at least 4 ft.
• Wall articulation: 30% of the upper side and rear wall needs 18-inch recesses.
• ADU in front of the house: allowed only when at least half the house sits in the rear third of a non-historic lot. Staff can approve a one-story unit, while larger two-story units need Planning Commission Chair sign-off, a porch or awning entry, a landscape plan, and street-facing windows.

These rules cover landmarks, historic district contributors, and homes on the city's inventory of eligible properties, a large share of South Pasadena.

• No attached ADUs: only conversions of accessory structures, new detached ADUs, and JADUs.
• Placement and scale: detached ADUs go at the rear, with at least half the front facade tucked behind the main house. The ADU can't be taller than the house (16 ft is always allowed), and it can only be two stories if the house is.
• Matching the house: roof form and material, cladding, doors, and windows must match the main house, and vinyl windows aren't allowed.
• Out of sight is exempt: a detached ADU that isn't visible from the street is exempt from these design rules. Units that don't comply go to the Cultural Heritage Commission.
• Old garages: demolishing any accessory structure 45 or more years old, or anything on a historic property, needs a Certificate of Appropriateness before the ADU application counts as complete, and may need a paid historic evaluation.

South Pasadena defines a high risk fire area south of Monterey Road and west of Meridian Avenue to the city limits. There, local rules get stricter:

• Sprinklers: always required in ADUs and JADUs.
• Parking: on streets narrower than 28 ft, one off-street space is required, and you can't displace the main house's parking. A garage conversion means replacing every space.
• Location: a detached ADU must be within 150 ft of the front property line, or on flag lots within 100 ft of a dry standpipe with Fire Chief approval.
• State fire map: city staff note that very high fire hazard designation brings wildfire-resistant construction (CBC Chapter 7A) and defensible space requirements.

• Protected trees: oaks, bay laurel, sycamore, toyon, black walnut, and several other natives 4 inches or more in diameter, plus heritage trees, need a tree removal permit, approved before your ADU application is complete. Trimming them needs a permit too.
• Hillsides: ADUs can sit within, behind, or under the house or a parking bridge, and a hillside development permit may be required first.

• Review: ministerial staff review, with a decision within 60 days of a complete application. Tree, historic, and hillside approvals come first.
• Online permits: South Pasadena launched an OpenGov portal on August 11, 2026 for building, planning, and tree permits.
• Impact fees: none under 750 sq ft. Larger ADUs pay in proportion to the main house, and units deed-restricted at or below 80% of AMI are exempt.
• Water and sewer: the city runs its own water and sewer utilities, and an ADU isn't charged as a new connection unless it's built with a new house.
• Planning fees: the city's ADU application says there's no planning processing fee, but a planning inspection fee and 10% technology surcharge apply. School fees are collected under state law.

• Parking: one space unless exempt, for example within half a mile of a bus stop or light rail, in a historic district, or inside the existing house. The fire area rules above can override these exemptions.
• Rentals: 30 days or more.
• Selling: ADUs can't be sold separately, except through a qualified nonprofit under state law.
• Occupancy: the ADU can't get its certificate of occupancy before the main house does.

Can I build an attached ADU on a historic property in South Pasadena?

No. Historic properties can have a detached ADU at the rear, a conversion of an accessory structure, or a JADU. Detached units visible from the street must match the main house's roof, materials, and windows.

What changes if my South Pasadena home is in the high risk fire area?

South of Monterey Road and west of Meridian Avenue, ADUs always need sprinklers, may need off-street parking on narrow streets, and detached units must sit within 150 ft of the front property line.

Can I tear down my old garage to build an ADU in South Pasadena?

Usually, but if the garage is 45 or more years old you'll need a Certificate of Appropriateness first, and possibly a historic evaluation.

How big can an ADU be in South Pasadena?

Detached ADUs can reach 1,200 sq ft. Attached ADUs are 850 sq ft with one bedroom or 1,000 sq ft with two or more.

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