ADU Rules in Pasadena (2026): What You Can Build

An accessory dwelling unit (ADU) is a self-contained second home — its own kitchen, bathroom, sleeping area and entrance — on the same lot as a house. Pasadena permits ADUs under California’s state ADU law (Government Code 66310–66342) and its own ordinance, Pasadena Municipal Code 17.50.275, last rewritten by Ordinance 7420 in May 2024. Green Design and Build is a licensed general contractor (CSLB #1110975) serving homeowners across Los Angeles County, Orange County, Ventura County, western Riverside County and western San Bernardino County, and the headline number for Pasadena is this: outside the Hillside Overlay, a detached ADU can be up to 1,200 sq ft and 18 feet tall with 4-foot side and rear setbacks. This page is part of our city-by-city ADU rules guide.

Who we are

Green Design and Build is led by Dekel Sofer. We hold a 4.7-star rating across 146 Yelp reviews and have completed hundreds of projects. We are a full-service residential general contractor in Pasadena and across Los Angeles County that builds ADUs alongside kitchens, bathrooms, additions and whole-home renovations — not an ADU-only company — and this page is a reference, not a pitch.

ADU rules in Pasadena at a glance

Rule	Pasadena (PMC 17.50.275)	State floor the city must allow
Detached ADU, maximum size	1,200 sq ft; 1,000 sq ft in the Hillside Overlay; 800 sq ft on hillside streets 26 ft wide or narrower	At least 800 sq ft with 4 ft side and rear setbacks regardless of lot coverage or floor-area limits
Attached ADU, maximum size	850 sq ft (studio or one bedroom); 1,000 sq ft (two or more bedrooms)	850 sq ft / 1,000 sq ft
Junior ADU (JADU)	500 sq ft, inside the house or attached garage; one per lot	500 sq ft
Height	Detached: 18 ft and two stories; 16 ft in the Hillside Overlay and for units visible from the street in a landmark or historic district; plus 2 ft within a half mile of a major transit stop if needed to match the roof pitch. Attached: 25 ft or the zone’s house height, whichever is lower	16 ft detached; 18 ft near transit; 25 ft attached
Setbacks	4 ft side and rear for new construction and expansions; none for conversions of existing space except what fire safety requires; front setback of the zone (state law says this cannot be used to block an 800 sq ft unit)	4 ft side and rear
Parking	Not required for conversions, for lots within a half mile of transit, in historic districts, or within a block of a car-share location; otherwise one space per unit or bedroom, whichever is less. No replacement parking when a garage is converted or demolished	No parking for state-exempt (800 sq ft) ADUs; no replacement parking
Owner-occupancy	Not required for an ADU. Required for a JADU (owner lives in the house or the JADU)	Cities may not require it for ADUs; JADU only if it shares a bathroom with the house
Units on a single-family lot	One ADU (attached or detached) plus one JADU	Conversion ADU + JADU + one detached 800 sq ft ADU
Short-term rental	Rentals must be longer than 30 days for units created on or after January 1, 2017	Longer than 30 days
Impact fees	Residential Impact Fee waived up to 900 sq ft (since July 17, 2025); above that, proportional to the house	Exempt at 750 sq ft or less; proportional above
Review timeline	15 business days to deem the application complete; 60 days to approve or deny; deemed approved if the city misses it	Same (Gov. Code 66317)
Where to apply	Pasadena Permit Center, 175 North Garfield Avenue (George Ellery Hale Building), (626) 744-4200; online through the Pasadena Citizen Self Service portal at cityofpasadena.net/mypermits	—

Size, height and setbacks

Pasadena’s ordinance sorts ADUs into two families. An “exemption ADU” is the unit state law makes every city approve: a detached building of no more than 800 sq ft and 16 feet with 4-foot side and rear setbacks, or a conversion of existing space. A “non-exemption ADU” is anything larger, and that is where Pasadena’s own numbers apply: 1,200 sq ft detached at 18 feet and two stories, 850 or 1,000 sq ft attached depending on bedrooms, a 6-foot eave-to-eave separation from other buildings, and no second-story windows facing a side or rear lot line where the setback is under 5 feet.

Three overlays change the arithmetic. In the Hillside Overlay District — Linda Vista, the San Rafael hills, Annandale, Upper Hastings Ranch and the foothill streets — a detached new ADU is limited to 1,000 sq ft and 16 feet, and on a street 26 feet wide or narrower to the 800 sq ft exemption size. In the landmark and historic districts, a non-exemption ADU cannot be visible from the public right-of-way unless that would prevent the unit altogether, and a visible unit drops to 16 feet. In the Very High Fire Hazard Severity Zones along the foothills, the ADU is built to Chapter 7A ignition-resistant standards.

Underneath all of it sits the state floor: an 800 sq ft ADU with 4-foot side and rear setbacks must be allowed regardless of lot coverage, floor-area ratio, open-space or front-setback rules (Gov. Code 66321(b)(3)). Run your lot through our ADU rules calculator to see which numbers apply.

Garage conversions and JADUs in Pasadena

A garage, carriage house, pool house or other accessory structure can be converted to an ADU with no size limit and no new setbacks beyond what fire safety requires, and the conversion may add up to 150 sq ft solely for ingress and egress — a stair or entry vestibule, not an extra room. Pasadena does not require the lost parking to be replaced, and in East Pasadena and Hastings Ranch the two-car garage on a flat lot is the most common garage conversion we see. Fire sprinklers follow the main house: if the house is not sprinklered, the ADU cannot be required to be.

A junior ADU is up to 500 sq ft carved out of the house or its attached garage, with its own entrance and an efficiency kitchen; it can share a bathroom with the house, and Pasadena allows one alongside a detached ADU on the same lot. The catch is owner-occupancy: Pasadena requires the owner to live in either the house or the JADU and records a covenant before the permit is issued; state law now only imposes that on a JADU that shares a bathroom with the house. Neither unit can be sold separately from the house except through a qualified nonprofit.

Pre-approved plans, fees and utilities

Pasadena runs its own ADU Standard Plans Program. At the time of writing the plan open to any homeowner is Prototype A, a 374 sq ft studio provided at no cost; four more plans (400 to 750 sq ft) are reserved for properties red-tagged in the Eaton Fire. Standard plans cannot be modified at all, site-specific items (foundation, grading, hillside geotechnical report, energy compliance) are still checked, and the city quotes a 3-to-4-week review. The LA ADU Standard Plan Program is a separate LADBS catalogue and does not apply in Pasadena.

Fee categories are plan check, building permit and inspections, separate mechanical and electrical permits, the Residential Impact Fee, Construction Tax, General Plan Maintenance Fee, Technology Fee, a refundable Construction and Demolition deposit, an addressing fee, PWP connection charges, and school fees, which Pasadena Unified may levy on an ADU over 500 sq ft. Since May 2025 the city has trimmed most of them: units of 900 sq ft or less are exempt from the Residential Impact Fee and get 25 percent off the Construction Tax, General Plan Maintenance Fee and Technology Fee; units built from a Standard Plan or under a seven-year Housing Agreement (a family member, the city’s rental-assistance clients, or rents at 120 percent of area median income) get a 50 percent plan-check discount and a full waiver of those four fees; and every ADU’s C&D deposit is a flat, refundable $1,000.

Pasadena Water and Power, not Southern California Edison, is the utility. Under state law (Gov. Code 66324, numbered 66311.5 in the current HCD handbook) a conversion ADU or JADU cannot be forced onto a separate utility connection or charged a connection fee; a new-construction ADU can be, with a fee proportionate to its size.

The permit process in Pasadena, step by step

1. Confirm the overlays. Check the address on the city’s zoning map for the Hillside Overlay, landmark districts and the fire hazard zone.
2. Book a virtual consultation and a PWP appointment. Planning offers preliminary feedback, and the city’s checklist has you see Pasadena Water and Power about utility conflicts early.
3. Prepare the set. Site plan, floor plans, elevations, structural calculations, Title 24 energy compliance, and trade sheets as needed.
4. Submit online. File the ADU and addressing applications on the Pasadena Citizen Self Service portal (cityofpasadena.net/mypermits) and pay plan check fees; the Permit Center at 175 North Garfield Avenue is on reduced hours during its 2026 renovation.
5. Plan check. Planning, Building and Safety, Fire, Public Works and PWP review the set. The city has 15 business days to deem it complete and 60 days to act; corrections and utility clearances (LA County Sanitation, SoCalGas, PWP) go back through the portal.
6. Permit issuance. Pay the permit, inspection and impact fees and pull the separate mechanical and electrical permits.
7. Construction and inspections. Foundation, framing, rough trades, insulation, drywall and final, requested through the portal or by phone.
8. Certificate of Occupancy. Issued after final sign-off and utility connection.

End to end, a Pasadena ADU usually runs six months to a year; the 60-day plan-check clock is only the middle of that.

What an ADU costs in Pasadena

Our published figures are budgeting ranges, not quotes: a garage conversion ADU typically runs $100,000–$200,000; a detached 500 sq ft ADU $180,000–$260,000; 700–800 sq ft $225,000–$350,000; and 1,000 sq ft $300,000–$450,000 and up. The rule of thumb is $300–$450 per sq ft all-in, and $500 or more per sq ft on difficult lots. Pasadena adds two cost drivers of its own: hillside lots carry a geotechnical report, an engineered foundation and often a retaining wall, and landmark-district lots need an exterior that reads as period-appropriate from the street — real wood windows and matching roof pitch and siding rather than off-the-shelf substitutes. Our post on how much it costs to build an ADU walks through a real detached project line by line.

Frequently asked questions

How big can a detached ADU be in Pasadena?

A detached new-construction ADU in Pasadena can be up to 1,200 sq ft and 18 feet tall with two stories, with 4-foot side and rear setbacks, under Pasadena Municipal Code 17.50.275. In the Hillside Overlay District the limit drops to 1,000 sq ft and 16 feet, and to 800 sq ft on streets 26 feet wide or narrower. State law requires Pasadena to allow at least an 800 sq ft unit on any lot.

Do I need parking for an ADU in Pasadena?

Pasadena does not require parking for an ADU converted from existing space, on a lot within a half mile of transit, in a historic district, or near a car-share location; otherwise it asks for one space per unit or bedroom, whichever is less, which can be tandem on the driveway. Under state law a detached ADU of 800 sq ft or less cannot be required to provide parking. Replacement parking is never required when a Pasadena garage becomes an ADU.

Can I build an ADU in a Pasadena landmark district like Bungalow Heaven?

Yes, an ADU can be built on a landmark-district or individually designated historic property in Pasadena, but a non-exemption ADU cannot be visible from the public right-of-way unless that rule would prevent the unit entirely, and a visible unit is limited to 16 feet. Conversions, 800 sq ft exemption ADUs and JADUs are all permitted. It is a design problem rather than a prohibition.

Do I have to live on the property to have an ADU in Pasadena?

No, Pasadena does not require owner-occupancy for an ADU, and state law now permanently prohibits cities from imposing that requirement. A junior ADU is different: Pasadena requires the owner to live in either the main house or the JADU and records a covenant before the permit is issued. Both must be rented for terms longer than 30 days.

What does Pasadena charge in ADU impact fees?

Pasadena waives its Residential Impact Fee for ADUs of 900 sq ft or less, a wider exemption than the 750 sq ft floor in state law, and for an ADU of any size built under a seven-year Housing Agreement or from a city Standard Plan. Units over 900 sq ft without an agreement pay a fee proportional to the size of the main house. Since May 2025 the city has also cut plan-check and permit fees for most ADUs.

How long does an ADU permit take in Pasadena?

Pasadena has 15 business days to determine that an ADU application is complete and 60 days to approve or deny it, after which state law deems it approved; Standard Plan applications are quoted at three to four weeks. End to end, a Pasadena ADU takes six months to a year from design to Certificate of Occupancy, with hillside and landmark-district projects at the longer end.

Find out what your Pasadena lot allows

Send us the address and we will check the Hillside Overlay, landmark-district and fire-zone status, tell you which ADU sizes apply, and follow up with a free site visit and a written, itemized estimate. Everything runs through Pasadena's Permit Center and PWP, and we handle the submittal, corrections and inspections.