In Pasadena, ADU permits go through the Planning & Community Development Department and its Permit Center, which offers walk-in hours and virtual appointments. Applications are filed online through the city's Citizen Self-Service portal. State ADU law applies, and Pasadena adds its own standards for spacing, windows near property lines and equipment.
What kind of homes and lots does Pasadena have?
Much of Pasadena's housing is older, including Craftsman bungalows and period revival homes, and the city has designated historic and landmark districts. Older homes often come with detached garages near the back of the lot, which can be strong garage conversion candidates if the structure is sound. West of the Arroyo Seco, toward the San Rafael Hills, lots turn to hillside terrain, where slope and soils change what is practical.
Does Pasadena have a pre-approved ADU plan?
Yes, with limits. As of October 2026, Pasadena's original ADU standard plans expired on December 31, 2025, with the new building code cycle. The plan open for general use is Prototype A, a 374 sq ft studio updated to the 2025 California Building Code and free to use on most single-family properties. The other standard plans are limited to properties red-tagged after the Eaton Fire. The city does not allow changes to standard plans.
What site rules does Pasadena list for its standard plans?
As of October 2026, the city's standard plan page lists these site conditions, which are a useful preview of how Pasadena looks at any ADU:
- 4-foot setbacks from side and rear property lines, and at least 5 feet for walls with windows or doors.
- At least 6 feet between the ADU and other structures, eave to eave, unless the ADU is under 800 sq ft.
- The lot cannot be on a slope, hillside or expansive soil site; a geotechnical report may be required.
- Air conditioners and heat pumps at least 5 feet from the property line and screened from the street.
- Front setback, lot coverage, floor area ratio and encroachment plane rules of the zone still apply.
- Every ADU needs its own address.
A custom design is the usual path for hillside lots or for a unit larger than the studio prototype.
How long does Pasadena take to review ADU plans?
For standard plans, the city states as of October 2026 that the completeness check takes 1 to 2 business days, plan check about 3 to 4 weeks, and resubmittals about 2 weeks. Custom designs follow the regular plan-check process, within the state's 60-day limit once an application is complete.
What if my home is in a historic district?
State law limits what any city can require of an ADU, and an ADU in an architecturally and historically significant historic district cannot be required to provide parking. Historic properties can still carry specific standards. If your house is in a Pasadena historic or landmark district, we confirm with Planning what applies before design starts.
What does Pasadena ADU work depend on?
- The age and condition of the existing garage or house.
- Slope, soils and access on hillside lots.
- Utility connections, which in Pasadena involve the city's own water and power utility.
- Residential impact fees for units over 750 sq ft, and fire sprinkler requirements where they apply.