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

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 catalog 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 July 17, 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 66311.5, formerly 66324) 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. The city also cut plan-check and permit fees for most ADUs: the first cuts took effect in May 2025, and the Residential Impact Fee and Construction Tax reductions on July 17, 2025 (City of Pasadena ADU page).

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.

The state has found Pasadena’s ADU ordinance out of compliance

On 26 February 2025 the California Department of Housing and Community Development reviewed Ordinance 7420 and concluded that Pasadena’s ADU ordinance does not comply with state ADU law. The letter lists six problems. Four of them change what a homeowner can actually ask for:

• The ordinance still cites Government Code sections 65852.2, 65852.22 and 65852.26, which were deleted on 25 March 2024 and replaced by sections 66310–66342.
• It allows only one “exemption ADU” on a single-family lot. State law requires a city to allow a combination — “one converted ADU; one detached, new construction ADU; and one JADU.”
• It keeps a newly built ADU out of the front yard, where state law requires that at least an 800 sq ft ADU with four-foot side and rear setbacks be possible.
• Its parking standards go beyond what the statute permits, and its attached-ADU height language is ambiguous enough that HCD flagged it as potentially limiting.

What this means in practice: where a local ordinance is more restrictive than the statute, the statute controls. Pasadena’s published ADU page still lists Ordinance 7420 as the operative rules and we found no later amendment as of this review, so plan on the counter applying the ordinance as written — and know that the HCD letter, linked in the sources below, is the document to put in front of a plan checker who denies something the state floor protects. We would rather design to the state floor from the start than argue it later.

Sources

Pasadena’s ADU rules come from the city’s own ordinance and from California ADU law, and as of this review the two do not fully match. The Legislature amends ADU law most years and the city amends its ordinance on its own schedule. Confirm both before you design, and note the review date below.

• City of Pasadena, Accessory Dwelling Units — the city’s own ADU page: updated ADU and JADU regulations took effect 20 May 2024 under Ordinance No. 7420, a JADU is “limited to a maximum area of 500 square feet”, and applications are filed through the city’s permit portal.
• Pasadena Ordinance No. 7420 — “An Ordinance of the City of Pasadena Amending Various Sections of Title 17 (Zoning Code)”, adopted 15 April 2024, effective 30 days after publication. This is the ordinance that rewrote Pasadena Municipal Code section 17.50.275 on ADUs and JADUs.
• California HCD, review of Pasadena’s ADU ordinance (26 February 2025) — the state’s formal review of Ordinance 7420, which concluded that the ordinance does not comply with state ADU law and listed six specific problems, among them outdated Government Code references, the number of ADUs allowed together on a single-family lot, a front-yard restriction, and the parking standards. Where a local ordinance is more restrictive than the statute, the statute controls.
• California HCD, Accessory Dwelling Unit fact sheet (April 2026) — the state floor in the table above: Government Code sections 66310–66342, the 60-day decision deadline (section 66317), four-foot rear and side setbacks, and no impact fees on an ADU of 750 sq ft or less or on a JADU.
• California HCD, Accessory Dwelling Unit Handbook (March 2026) — Government Code section 66321(b)(3), which bars local standards that would “not permit at least an 800 square foot accessory dwelling unit with four-foot side and rear yard setbacks”.

Last reviewed 17 September 2026.

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.