Everything homeowners ask about building an ADU in Pasadena — answered with 2026 data.
Yes, ADUs are allowed in All zoning districts that permit single-family or multifamily residential uses, on lots with at least one existing or proposed dwelling (PMC 17.50.275.B.1). JADUs only on lots with a single-family dwelling (17.50.275.E.1). In Landmark and Historic Districts and on designated historic properties, a new ADU larger than 800 sq ft may not be visible from the public right-of-way unless that would prevent the unit (17.50.275.D.2). in Pasadena, CA. The maximum size for a detached ADU is 1,200 sq ft for a new detached ADU on a single-family lot (17.50.275.D.1.a). Hillside Overlay lots outside HD-1: 1,000 sq ft, or 800 sq ft where the street pavement is 26 ft wide or narrower (D.1.b). Conversions of existing space have no size limit. Floor area may be measured by the Zoning Code or the California Building Code, whichever the applicant prefers (D.1.d). Attached ADUs can be up to 850 sq ft for a studio or one-bedroom and 1,000 sq ft for two or more bedrooms. Pasadena has an ADU-friendliness score of 7/10. Check our full Pasadena ADU rules page for complete zoning details.
ADU construction in Pasadena typically costs $150,000-$400,000. The cost per square foot averages $300-$450. Garage conversions are more affordable at $120,000-$190,000, while prefab ADUs cost $180,000-$300,000. Permit fees add Valuation-based (FY2027 General Fee Schedule, adopted June 8, 2026): building permit $1,738 plus $6 per $1,000 over $100,000; plan check $2,607 plus $9 per $1,000; Construction Tax 1.92%; General Plan and Technology fees 0.5% each; refundable C&D deposit flat $1,000; new address $345. to your budget. See our detailed Pasadena ADU cost guide.
Detached ADUs in Pasadena can be up to 1,200 sq ft for a new detached ADU on a single-family lot. Attached ADUs are limited to 850 sq ft for a studio or one-bedroom and 1,000 sq ft for two or more bedrooms. Junior ADUs (JADUs) have a cap of 500 sq ft, built inside the existing or proposed single-family home or its attached garage, with an efficiency kitchen and its own exterior entrance; may share a bathroom with the house (17.50.275.E.2). Maximum height is New detached ADU: 18 ft and 2 stories, plus 2 ft within 1/2 mile of a major transit stop to match the main roof pitch; 16 ft in Hillside Overlay districts, in Landmark/Historic Districts when visible from the street, or for an exemption ADU in the front setback (18 ft there if the site has a multistory building or is near major transit). New attached ADU: 25 ft or the zone limit, whichever is less, up to 2 stories. Multifamily lots: 16 ft, 18 ft if multistory or near transit (17.50.275.D.3.c). You are allowed up to Single-family lot: one new-construction ADU, one conversion ADU and one JADU on a qualifying lot.
Rear setback: 4 ft for new construction and for any addition to a conversion ADU. No setback beyond fire-safety needs for a conversion of existing space or for a rebuild in the same location, dimensions and height (17.50.275.D.3.a). Side setback: 4 ft for new construction; none for conversions except fire safety (17.50.275.D.3.a). A new ADU over 800 sq ft must also keep 6 ft eave-to-eave from any other building on the lot (D.3.b), and its second-story windows facing an interior side or rear line closer than 5 ft must be clerestory unless the Building Code requires otherwise (D.3.d). Front setback: An exemption ADU of 800 sq ft or less may sit 4 ft from the front lot line (17.50.275.B.2.a, as amended by Ordinance 7471). A new ADU larger than 800 sq ft must meet the front setback of the underlying zone (D.3.a). Note that garage conversions may be exempt from setback requirements if the existing structure is already within the setback area.
1 space per ADU on a single-family lot, allowed uncovered or tandem on the driveway; none required on multifamily lots. Waived for an 800 sq ft exemption ADU, within 1/2 mile walking distance of public transit, for a conversion of existing space, in a historic district, or with car share within one block. No replacement parking when a garage or carport is converted (17.50.275.D.4). Many cities and states have been relaxing ADU parking requirements in recent years. In California, no additional parking is required for ADUs near transit.
None for ADUs. A JADU that shares a bathroom with the main house requires the owner to live in either unit and a recorded covenant before permit issuance (17.50.275.E.3, E.5); a JADU with its own bathroom has no owner-occupancy rule, consistent with AB 1154 (eff. Jan 1, 2026). Note that owner-occupancy rules vary by state law — California and several other states have eliminated this requirement for standard ADUs.
The ADU permit review timeline in Pasadena is typically 60 days from a complete application for the city to act, or the ADU is deemed approved (Gov. Code 66317; SB 543 from Jan 2026). For Standard Plan submittals the city publishes about 3-4 weeks for first plan check and about 2 weeks per resubmittal. Plan check: Plan check is 50% off for ADUs using a city Standard Plan or with a Housing Agreement (affordability covenant or landlord agreement), and those units also skip the Construction Tax, General Plan Maintenance and Technology fees. ADUs of 900 sq ft or less without an agreement get 25% off those three items. Single-family sites only; reductions are not retroactive (effective May 6, 2025). Pre-approved plans availability: Yes. As of August 2026 one free city Standard Plan compliant with the 2025 California Building Code is available citywide: Prototype A, a 374 sq ft studio. The five earlier plans (374-750 sq ft) expired Dec 31, 2025 and may only be used on properties red-tagged in the Eaton Fire. Plans cannot be modified, and a Hold Harmless Agreement is required.
Average ADU rental income in Pasadena: 1-bedroom units rent for $2,300-$3,000/month, 2-bedroom units for $3,100-$3,750/month. Short-term rentals: No. An ADU or JADU legally created on or after Jan 1, 2017 may only be rented for terms longer than 30 days, and neither may be sold separately from the main home except by a qualified nonprofit under Gov. Expected ROI: 7-11% gross rental yield on a $400,000 detached build at $2,300-$3,750/mo, higher for a garage conversion (estimate before taxes, vacancy and financing).
The minimum lot size for an ADU in Pasadena is None. PMC 17.50.275 sets no minimum lot size; any lot in a zone that allows residential use with an existing or proposed dwelling qualifies (17.50.275.B.1). This applies to detached ADUs — garage conversions and JADUs may have different or no lot size requirements.
Garage conversions are one of the most popular and affordable ADU options. In Pasadena, a garage conversion typically costs $120,000-$190,000. The key advantages are lower cost (no foundation work), potential setback exemptions, and faster permitting. Read our complete garage conversion guide.
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