Pasadena ADU rules and requirements

Yes, you can build an ADU on any Pasadena lot that allows housing. A new backyard unit on a single-family lot is 800 sq ft with no zoning review, or up to 1,200 sq ft if it meets the zone's normal rules. Most lots need no parking. City fees run roughly $12,000 for an 800 sq ft unit, about $5,000 if you use the city's free standard plan, and the city has 60 days to decide once your application is complete.

Backyard unit: 800 sq ft exempt, up to 1,200 sq ft with zone rules²
Parking: None for most units²
City permit fees: Roughly $12,000 at a $200,000 valuation; about $5,000 with the free standard plan⁷⁸
Decision: Within 60 days¹⁵

Figures read from the city's own documents, last checked 20 September 2026. Each number links to its source.

Who to call: Pasadena Planning & Community Development Department, Current Planning Division, 626-744-4009 (planning), 626-744-4200 (Permit Center). Permit Center, 175 N. Garfield Ave, Pasadena, CA 91101. ZoningQuestions@cityofpasadena.net.¹¹¹

Under state review. Pasadena rewrote its ADU rules in April 2026 to fix six problems the state flagged, and the state's sign-off on the rewrite is not yet posted. The rules below are the April 2026 version, Ordinance 7464. Where they conflict with state law, the ordinance itself says state law wins.²³⁴⁵

The rules at a glance

"City rule" means Pasadena set the figure. "State rule" means the city applies the state minimum, which no city can go below.

ADU rules in Pasadena
Backyard unit, max size City rule	800 sq ft for a new detached unit that the city must approve without zoning review, on a single-family lot. Go up to 1,200 sq ft and the unit has to fit the zone's usual limits on lot coverage, floor area and front setback. Converting a garage or other existing building has no size cap, and you can add 150 sq ft for an entry. In a hillside overlay the cap is 1,000 sq ft, or 800 sq ft on a narrow street. The smallest unit allowed is 150 sq ft.²
Attached unit, max size City rule	800 sq ft as an exempt unit. Bigger than that, the city allows 850 sq ft for a studio or one-bedroom and 1,000 sq ft for two or more bedrooms, and the unit must meet the zone's normal rules. State law says the city cannot deny an attached unit up to half the size of your house, and the ordinance says state law wins in a conflict, so ask if you want more.²¹⁴
Junior unit, max size State rule	500 sq ft, carved out of the existing house or attached garage, with its own outside door and a small kitchen. Since April 2026 you can measure the area by the zoning code or the building code, whichever gives you the better number.²¹⁴
Height City rule	18 ft and two stories for most new detached units, plus 2 ft to match the house's roof pitch if you are within a half-mile walk of a major transit stop. It drops to 16 ft in a hillside overlay, in a historic district when the unit shows from the street, or when an exempt unit sits in the front setback (18 ft again if the lot is near transit or already has a two-story building). An attached unit can go to 25 ft and two stories, or the zone's limit if lower. You may measure height by the zoning code or the building code, your choice.²
Setbacks City rule	Four feet from the side and rear property lines for anything new. Units of 800 sq ft or less can sit in the front setback; bigger ones must respect the zone's front setback. Converting an existing building needs no setback beyond what fire safety requires, and you can rebuild it in the same footprint. Units over 800 sq ft also need 6 ft between eaves to any other building. The city's site-plan checklist asks that any wall with a window or door be at least 5 ft from the side or rear line, so plan openings on the inward-facing walls.²⁶
Parking City rule	None for an exempt unit (800 sq ft or less with 4 ft setbacks, or a conversion), none within a half-mile walk of a bus or train stop, none in a historic district, and none on a lot with an apartment building. Otherwise one space, which can be uncovered or tandem in the driveway. Converting a garage never requires replacing the parking you lose. The unit shares the existing driveway.²
Lot coverage and open space City rule	An exempt unit of 800 sq ft or less ignores the zone's lot coverage, floor area and open-space limits. Anything bigger has to fit them, along with the encroachment plane, and any garage, patio or deck attached to the unit must meet the zone's rules too.²¹⁴
Do you have to live there State rule	No, not for an ADU. For a junior unit that shares a bathroom with the house, you or the owner must live in one of the two, and a covenant saying so is recorded before the permit. A junior unit with its own bathroom has no owner-occupancy rule.²¹⁴
Renting it out State rule	Tenants must stay longer than 30 days. Nightly and weekly rentals are not allowed for any ADU or junior unit built since 2017. The unit cannot be sold apart from the house.²

Pasadena ADU permit fees

City permit fees
Building permit, new construction	Formula on the city's valuation of the work: $1,738 for the first $100,000 plus $6 per $1,000 above that. If the city values an 800 sq ft unit at $200,000, that is $2,338. FY 2027 General Fee Schedule, fee 325-335⁷
Plan check, all departments (building, fire, public works, planning, historic, transportation)	Building plan check is $2,607 for the first $100,000 plus $9 per $1,000 above; the five smaller reviews add about $1,216 at $100,000 plus $6 per $1,000. At a $200,000 valuation the six together come to about $5,320. Halved to about $2,660 with a city standard plan or a housing agreement. FY 2027 General Fee Schedule, fees 412-477⁷
Construction tax	1.92% of valuation, cut by 25% for a unit of 900 sq ft or less. About $2,880 at a $200,000 valuation. Waived with a standard plan or a housing agreement. FY 2027 Schedule of Taxes, Fees and Charges, PMC 4.32.020; city ADU page, reduced fees⁸¹
General plan maintenance and technology fees	0.5% of valuation each, cut by 25% for a unit of 900 sq ft or less: about $750 each, $1,500 together, at a $200,000 valuation. Waived with a standard plan or a housing agreement. FY 2027 General Fee Schedule, fees 321-322⁷
Residential impact fee	Nothing for a unit of 900 sq ft or less, or any size with a housing agreement. Over 900 sq ft the fee is the per-bedroom rate ($24,530 studio to $45,407 for five bedrooms) scaled by the unit's size divided by the main house's size. FY 2027 Schedule of Taxes, Fees and Charges, PMC 4.17.050 notes 10 and 11⁸
Construction and demolition deposit	$1,000 flat for every ADU on a single-family lot, refunded when you show the debris was recycled. FY 2027 General Fee Schedule, fee 1211⁷⁹
School fee (Pasadena Unified), collected at the Permit Center	$2.24 per sq ft on the district's 2023 sheet, so about $1,792 for 800 sq ft. Under state law units of 500 sq ft or less pay none. Ask for the current rate. PUSD Developer Fee Instructions, revised 2023-07-01¹³

How long it takes

Plan on the full 60 days plus one round of corrections; the city publishes review times only for standard plans. Water and Power, the county sanitation district and SoCalGas each sign off separately, so book the Water and Power meeting early.¹⁵⁶¹⁰

Completeness check: 15 business days for the city to tell you whether your application is complete. Standard-plan submittals get a completeness check in 1 to 2 business days.
Decision: 60 days after that to approve or deny, or the unit is approved by default
Pre-approved plans: About 3 to 4 weeks for plan check on a standard plan, 2 weeks per resubmittal

Does an ADU fit your lot in Pasadena?

The rules above are the city's. Whether they work on your lot depends on the lot. Type your address and we tell you yes, no, or yes with conditions, then connect you with one licensed builder who works in Pasadena. Free, and nobody calls unless you ask.

Check my address

Things to know before you build in Pasadena

Keep the unit at 900 sq ft or under. That one number switches off the residential impact fee (which starts around $24,500 before scaling) and takes 25% off the construction tax and two permit surcharges.
Sign the free housing agreement if you can. Rent to a family member or a city rental-assistance tenant for seven years and the city halves your plan check and waives the construction tax, impact fee and surcharges. It has to be signed before the permit is issued or the discount is lost.
The Permit Center's questionnaire asks three yes-or-no questions (standard plan, housing agreement, 900 sq ft or less) and sets your fees from the answers. Answer them carefully; a wrong answer means delays or a bill later.
Since April 2026 one lot can hold three units: a new one, a converted garage, and a junior unit inside the house. Book the free virtual ADU consultation before drawing anything.

Overlays that change the answer

Hillside overlay districts (HD, except HD-1). A new detached unit is capped at 1,000 sq ft, or 800 sq ft if your street is 26 ft wide or narrower, and height drops to 16 ft. Conversions have no size cap. A slope lot also needs a soils report and cannot use a standard plan.²⁶
Historic districts, landmark districts and designated historic properties. A unit bigger than 800 sq ft must not be visible from the street. A unit that does show from the street is limited to 16 ft. No parking is required anywhere in a historic district. Questions go to DHPQuestions@cityofpasadena.net.²¹
Eaton Fire red-tagged lots. The five expired standard plans (400 to 750 sq ft) can still be used on lots the city red-tagged after the January 2025 fire.⁶

Pre-approved ADU plans in Pasadena

Available One plan right now: Prototype A, a 374 sq ft studio the city designed, free to use, updated to the 2025 building code and posted in August 2026. The five earlier plans (400 to 750 sq ft) expired on 31 December 2025 and can only be used on lots red-tagged in the Eaton Fire. You cannot change a standard plan at all, but using one cuts plan check fees in half and waives the construction tax and two permit surcharges. The city checks your submittal for completeness in 1 to 2 business days and plan check takes about 3 to 4 weeks, with about 2 weeks per resubmittal. If you borrow through the city's Second Unit ADU Loan Program, a new detached unit must use a standard plan when one is available.⁶¹²

Questions people ask

How big can an ADU be in Pasadena?

A new backyard unit is 800 sq ft with no zoning review, or up to 1,200 sq ft if it fits the zone's coverage and setback rules. Converting a garage has no size cap. An attached unit is 800 sq ft exempt, or 850 to 1,000 sq ft depending on bedrooms. A junior unit inside the house is 500 sq ft. Hillside lots are capped at 1,000 sq ft, or 800 on narrow streets.

Do I need parking for an ADU in Pasadena?

Usually not. A unit of 800 sq ft or less, a conversion, a lot within a half-mile walk of transit, a lot in a historic district, or any lot with an apartment building needs none. Otherwise one space, which can be tandem in the driveway.

How much are ADU permit fees in Pasadena?

Fees are formulas on the city's valuation of the work. At a $200,000 valuation an 800 sq ft unit runs roughly $12,000 in permit, plan check, construction tax and surcharges, plus a refundable $1,000 deposit and about $1,800 in school fees. Using the city's free standard plan brings the city's share to about $5,000.

How long does an ADU permit take in Pasadena?

The city has 15 business days to say whether your application is complete and 60 days after that to decide, or the unit is approved by default. Standard-plan submittals are checked in 1 to 2 business days and reviewed in about 3 to 4 weeks.

Does Pasadena have pre-approved ADU plans?

One, free: a 374 sq ft studio the city designed, updated to the 2025 building code in August 2026. The older 400 to 750 sq ft plans expired at the end of 2025 and now only work on Eaton Fire red-tagged lots. Standard plans cannot be modified.

Does Pasadena help pay for an ADU?

The Second Unit ADU Loan Program lends up to $225,000 at 1% for three years to owner-occupants who rent the unit to city rental-assistance tenants for seven years, with a free project manager. Separately, anyone who signs a seven-year housing agreement gets plan check halved and the impact fee and construction tax waived.

What changed

1 August 2026 A new free standard plan, Prototype A (374 sq ft studio), was posted after being updated to the 2025 building code.
1 July 2026 FY 2027 fee schedule and schedule of taxes took effect (adopted 8 June 2026).
18 April 2026 Ordinance 7464 took effect: three units per single-family lot, no parking for exempt units, exempt units allowed in the front setback, two-story attached units, height and area measurable by the building code.
1 January 2026 AB 1154 took effect: a junior unit with its own bathroom no longer requires the owner to live on the property.
1 January 2026 SB 543 took effect: a 15-business-day completeness check and 60-day deemed approval under Gov. Code 66317.
31 December 2025 The city's five standard plans expired with the 2022 building code; they remain usable only on Eaton Fire red-tagged lots.
17 July 2025 Residential impact fee exemption raised to units of 900 sq ft or less; construction tax cut 25% under 900 sq ft and waived with a standard plan or housing agreement.
6 May 2025 Plan check halved for standard plans and housing agreements; general plan and technology fees cut 25% under 900 sq ft; C&D deposit set at a flat $1,000.
26 February 2025 HCD found Ordinance 7420 out of step with state law on six points, including the one-unit limit and parking for exempt units.
1 January 2025 AB 2533 took effect: the city cannot deny a permit to legalize an ADU built before 2020 unless it is a health or safety hazard.
20 May 2024 Ordinance 7420, the city's rewritten ADU rules, took effect.

Sources

Accessory Dwelling Units page (regulations, reduced fees, impact fees, housing agreements, contacts), City of Pasadena Planning & Community Development Department. Accessed 20 September 2026.
Ordinance No. 7464, Exhibit 10, PMC 17.50.275 Accessory Dwelling Units (adopted 2026-01-26, published 2026-03-19), City of Pasadena. Accessed 20 September 2026.
Ordinance No. 7420, ADU regulations (adopted 2024-04-15), City of Pasadena, via Municode. Accessed 20 September 2026.
Review of Pasadena's Accessory Dwelling Unit Ordinance, findings letter of 2025-02-26, California Department of Housing and Community Development. Accessed 20 September 2026.
Agenda Report, 2025 Zoning and Specific Plan Amendments, item 13 of 2025-10-27, City of Pasadena Planning & Community Development Department. Accessed 20 September 2026.
ADU Standard Plans Program page, City of Pasadena Planning & Community Development Department. Accessed 20 September 2026.
Fiscal Year 2027 General Fee Schedule, adopted 2026-06-08, City of Pasadena Finance Department. Accessed 20 September 2026.
Fiscal Year 2027 Schedule of Taxes, Fees and Charges, City of Pasadena Finance Department. Accessed 20 September 2026.
City of Pasadena Announces Reduced Fees to Support ADU Construction and Affordability, news release of 2025-05-06, City of Pasadena Office of the City Manager. Accessed 20 September 2026.
Permitting an Accessory Dwelling Unit, process diagram and contacts, City of Pasadena Planning & Community Development Department. Accessed 20 September 2026.
General Contact Information, Planning & Community Development Department, City of Pasadena. Accessed 20 September 2026.
Pasadena 2nd Unit ADU Loan Program handbook, 3rd round, revised December 2025, City of Pasadena Housing Department. Accessed 20 September 2026.
Developer Fee Instructions, revised 2023-07-01, Pasadena Unified School District. Accessed 20 September 2026.
Government Code sections 66310 to 66342, ADU law (link opens at section 66314), State of California. Accessed 20 September 2026.
Government Code section 66317, permit timelines (SB 543), State of California. Accessed 20 September 2026.

Nearby

Los Angeles County · Glendale · Los Angeles

Educational guidance drawn from the city's published rules, not a permit determination or a quote. Rules change; the date at the top is when these were last checked. Spotted a wrong figure? Tell us.