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Can I build an ADU in Pasadena, California?

Pasadena, Los Angeles County · Ordinances checked 2026-10-05 · Reviewed · 11 cited sections

Allowed with a permit

Yes. Pasadena allows ADUs on any lot zoned for homes that has a house, with a ministerial (no-hearing) permit. A single-family lot can have one new attached or detached ADU, one conversion ADU and one junior ADU; a new ADU up to 800 sq ft needs only 4-ft side and rear setbacks, and a larger detached ADU can be up to 1,200 sq ft.

Where allowedAll zones permitting single-family or multifamily homes, on lots with a home [1]
Units on a single-family lot1 new-construction ADU + 1 conversion ADU + 1 junior ADU [2]
Max size, new detached ADU1,200 sq ft (800 sq ft gets the most flexible 'exemption' rules) [4]
Max size, new attached ADU850 sq ft (studio/1-bed); 1,000 sq ft (2+ bedrooms) [5]
Side and rear setback4 ft for new ADUs [6]
Max height, detached18 ft and two stories (16 ft in hillside/historic cases) [7]
Junior ADU max size500 sq ft [9]
Parking1 space, waived for 800 sq ft 'exemption' ADUs, near transit, conversions and historic districts [8]
Owner-occupancyOnly for a junior ADU sharing a bathroom with the house [10]
Minimum rental termLonger than 30 days [11]

Where and how many

ADUs are permitted in every zone that allows single-family or multifamily homes, on a site with at least one existing or proposed dwelling [1]. On a single-family lot you can have one new-construction ADU (attached or detached), one conversion ADU and one junior ADU [2]. The Director reviews ADU permits ministerially within state deadlines, and state law prevails if it conflicts with the city's section [3].

Size

"Exemption" ADUs get the simplest rules: a new ADU up to 800 sq ft with 4-ft side and rear setbacks, or a conversion of existing space (no size limit, plus up to 150 sq ft for an entrance) [2]. Larger new ADUs must follow the zone's other standards (floor area, lot coverage, encroachment plane) and are capped at 1,200 sq ft detached [4] or 850 sq ft (studio/one-bedroom) and 1,000 sq ft (more bedrooms) attached [5]. In Hillside Overlay Districts, lots on streets 26 ft wide or less are limited to 800 sq ft for new ADUs, and other hillside lots to 1,000 sq ft detached.

Setbacks and height

New ADUs and expansions need 4-ft side and rear setbacks [6]; a straight conversion needs none except for fire safety. ADUs over 800 sq ft must meet the front setback. Detached ADUs may be 18 ft and two stories [7]; the limit is 16 ft for hillside ADUs, those visible from the street in historic districts, and exemption ADUs in the front setback. Attached ADUs may be up to 25 ft or the zone's limit, whichever is less.

Parking, junior ADUs and rentals

One parking space is required, but not for exemption ADUs, sites within a half-mile walk of transit, conversions, historic districts or near car share; garage conversions need no replacement parking [8]. Junior ADUs are up to 500 sq ft inside the house with an efficiency kitchen [9]; owner-occupancy applies only when the JADU shares a bathroom, and a covenant must be recorded [10]. ADUs created since 2017 can't be rented for 30 days or less [11], and can't be sold separately.

State ADU law changes often. Starting January 1, 2027, state law (AB 956) will require cities to approve two new detached ADUs on a single-family lot, which may override Pasadena's limit of one new-construction ADU; today the city's limit stands.

See how Pasadena compares with 8+ other California towns on accessory dwelling units (adus) →

Next steps

  1. Check your zone and whether the lot is in a Hillside Overlay or landmark/historic district (size, height and visibility limits differ).
  2. Decide whether the project fits the 800 sq ft 'exemption ADU' path (4-ft setbacks, no parking) or the larger non-exemption path.
  3. Submit plans to the Planning & Community Development Permit Center (175 N. Garfield Ave.) for ministerial ADU review and a building permit.
  4. For a junior ADU sharing a bathroom, record the owner-occupancy covenant before the building permit is issued.

Common questions

Can I build an ADU in Pasadena, California?
Yes. Pasadena allows ADUs on any lot zoned for homes that has a house, with a ministerial (no-hearing) permit. A single-family lot can have one new attached or detached ADU, one conversion ADU and one junior ADU.
How big can an ADU be in Pasadena, California?
A new detached ADU can be up to 1,200 sq ft, with 800 sq ft getting the most flexible 'exemption' rules. A new attached ADU is capped at 850 sq ft for a studio or 1-bedroom and 1,000 sq ft for 2 or more bedrooms. A junior ADU can be up to 500 sq ft.
What setbacks does an ADU need in Pasadena, California?
New ADUs need 4-ft side and rear setbacks. Detached ADUs can be 18 ft and two stories, or 16 ft in hillside or historic cases. Check whether your lot is in a Hillside Overlay or historic district, since limits differ there.
Does an ADU need parking in Pasadena, California?
It needs 1 space, but parking is waived for 800 sq ft 'exemption' ADUs, ADUs near transit, conversions and ADUs in historic districts.
Can I rent out an ADU in Pasadena, California?
Yes, but the minimum rental term is longer than 30 days. Owner-occupancy is required only for a junior ADU that shares a bathroom with the house.

California's statewide ADU law

California's ADU law (Gov. Code §§66310–66342, recodified from §65852.2; latest amendments effective January 1, 2026) overrides conflicting city rules, including in charter cities. Cities must approve ADUs ministerially (no hearing) within 60 days of a complete application, or the permit is deemed approved.

What cities cannot require or do:

  • Owner-occupancy for an ADU.
  • A minimum lot size.
  • Side or rear setbacks over 4 feet for a new ADU, or any setback for a converted existing structure.
  • Size, lot coverage or floor-area rules that block an ADU of at least 800 sq ft. Size caps can't be under 850 sq ft (1,000 for 2+ bedrooms).
  • Parking within half a mile walking distance of public transit, or replacement parking for a garage converted to an ADU.
  • Impact fees on ADUs of 750 sq ft or less.

By right on a single-family lot: one converted ADU plus one junior ADU (JADU, up to 500 sq ft inside the house), plus one new detached ADU (up to 800 sq ft, 16 ft tall). Owner-occupancy may be required only for a JADU that shares a bathroom.

Short-term rentals: cities may bar ADU rentals under 30 days, and must for by-right ADUs, JADUs and SB 9 units.

Coming January 1, 2027: AB 956 raises the by-right count to two new detached ADUs per single-family lot.

SB 9 (§§65852.21, 66411.7) allows two homes on a single-family lot, or a split into two lots of at least 1,200 sq ft (with a 3-year owner-occupancy affidavit).

State sources: Gov. Code §66314 (ADU ordinance standards) · Gov. Code §66315 (no owner-occupancy requirement) · Gov. Code §66317 (ministerial review, 60-day deadline) · Gov. Code §66321 (size, setback and height limits on local rules) · Gov. Code §66322 (parking exemptions) · Gov. Code §66323 (by-right ADUs and JADUs) · Gov. Code §66333 (junior ADUs) · Gov. Code §66311.5 (impact fees) · AB 956 (2026), Stats. 2026, ch. 791 · Gov. Code §65852.21 (SB 9 two-unit projects) · Gov. Code §66411.7 (SB 9 urban lot splits) · HCD, Accessory Dwelling Units (ADU Handbook, updated March 2026)

What the ordinance says

Exact text from Pasadena's published ordinances. Section numbers are as printed in the source.

  1. Sec. 17.50.275.B.1, Zoning Code Chapter 17.50 - Standards for Specific Land Uses (ADUs 17.50.275, accessory structures 17.50.250, home occupations 17.50.110, short-term rentals 17.50.296)
    ADUs are permitted in all zoning districts that permit single-family or multifamily dwelling residential uses on sites with at least one proposed or existing dwelling.
  2. Sec. 17.50.275.B.2.a(1), Zoning Code Chapter 17.50 - Standards for Specific Land Uses (ADUs 17.50.275, accessory structures 17.50.250, home occupations 17.50.110, short-term rentals 17.50.296)
    One detached or attached new construction ADU, one detached or attached conversion ADU, and one Junior ADU, subject to the development standards set forth in 17.50.275 D and E.
  3. Sec. 17.50.275.A.1, Zoning Code Chapter 17.50 - Standards for Specific Land Uses (ADUs 17.50.275, accessory structures 17.50.250, home occupations 17.50.110, short-term rentals 17.50.296)
    In the event of a conflict between this section and applicable state law, state law shall prevail.
  4. Sec. 17.50.275.D.1.a(3)(a), Zoning Code Chapter 17.50 - Standards for Specific Land Uses (ADUs 17.50.275, accessory structures 17.50.250, home occupations 17.50.110, short-term rentals 17.50.296)
    New construction detached ADU: Maximum area of 1,200 square feet.
  5. Sec. 17.50.275.D.1.a(3)(b), Zoning Code Chapter 17.50 - Standards for Specific Land Uses (ADUs 17.50.275, accessory structures 17.50.250, home occupations 17.50.110, short-term rentals 17.50.296)
    New construction attached ADU: Maximum area of 850 square feet for a studio or one-bedroom, and 1,000 square feet for more than one bedroom.
  6. Sec. 17.50.275.D.3.a(2), Zoning Code Chapter 17.50 - Standards for Specific Land Uses (ADUs 17.50.275, accessory structures 17.50.250, home occupations 17.50.110, short-term rentals 17.50.296)
    Side and Rear Lot Lines: Four feet for newly constructed ADUs and expansions to conversion ADUs.
  7. Sec. 17.50.275.D.3.c(2)(b), Zoning Code Chapter 17.50 - Standards for Specific Land Uses (ADUs 17.50.275, accessory structures 17.50.250, home occupations 17.50.110, short-term rentals 17.50.296)
    A maximum of 18 feet and two-stories in height for all other ADUs.
  8. Sec. 17.50.275.D.4.a, Zoning Code Chapter 17.50 - Standards for Specific Land Uses (ADUs 17.50.275, accessory structures 17.50.250, home occupations 17.50.110, short-term rentals 17.50.296)
    One parking space per unit on a single-family site shall be provided for the ADU. The on-site parking space may be provided as covered, uncovered, or as tandem parking on an existing driveway.
  9. Sec. 17.50.275.E.2.e, Zoning Code Chapter 17.50 - Standards for Specific Land Uses (ADUs 17.50.275, accessory structures 17.50.250, home occupations 17.50.110, short-term rentals 17.50.296)
    Maximum unit size for a Junior ADU is 500 square feet.
  10. Sec. 17.50.275.E.3, Zoning Code Chapter 17.50 - Standards for Specific Land Uses (ADUs 17.50.275, accessory structures 17.50.250, home occupations 17.50.110, short-term rentals 17.50.296)
    For Junior ADUs which share a sanitation facility, either the primary unit or the Junior ADU shall be owner-occupied.
  11. Sec. 17.50.275.E.4, Zoning Code Chapter 17.50 - Standards for Specific Land Uses (ADUs 17.50.275, accessory structures 17.50.250, home occupations 17.50.110, short-term rentals 17.50.296)
    Any rental term of a Junior ADU that was legally created on or after January 1, 2017 shall be longer than 30 days.
This page summarizes Pasadena's posted ordinances as of 2026-10-05. Ordinances are amended, and individual lots can have overlays, subdivision covenants, or HOA rules that are stricter. Confirm with Planning & Community Development Department - Code Compliance, 175 N. Garfield Avenue (Permit Center/Building & Safety 626-744-4200) (626-744-8633) before you build. Spot an error?