You can almost certainly build an ADU in Pasadena. California law requires every city to allow at least one ADU and one junior ADU on a single-family lot, protects an 800 square foot unit with four-foot side and rear setbacks at 16 feet of height, bars cities from requiring replacement parking for a garage conversion, and gives the city 60 days to approve or deny a complete application. Pasadena applies its own design standards and fees on top of that floor.
- Building department
- Pasadena Planning & Community Development
- State floor
- 800 sq ft protected4 ft setbacks, 16 ft height
- Decision deadline
- 60 daysOn a complete application
- Typical all-in cost
- $120k to $400kConversion through detached
What state law guarantees you, here and everywhere
- At least one ADU and one junior ADU on a single-family lot
- An 800 square foot unit with 4-foot side and rear setbacks at 16 feet of height, which no local lot-coverage, floor-area or open-space rule can block
- 18 feet of height near major transit or on a lot with an existing multi-storey multifamily building, plus 2 feet to match the main roof pitch
- No replacement parking when you convert a garage
- No owner-occupancy requirement for a full ADU
- A decision within 60 days of a complete application, with 15 business days for the city to confirm completeness
A city cannot opt out of these. Where a local ordinance conflicts with state law, state law governs, and local ADU ordinances that are not properly submitted to the state housing department can be void entirely.
What is specific to Pasadena
Pasadena reviews ADU applications through its own planning and building divisions rather than LADBS, and runs its own fee schedule. The state's 60-day decision clock applies here exactly as it does everywhere else in California.
The thing that most shapes an ADU in Pasadena is historic status. The city has designated landmark districts and individually designated properties, and on those, exterior work visible from the street gets reviewed. A detached unit in a rear yard, screened from the street, is usually far simpler than one that changes the street-facing elevation.
Pasadena's older housing stock also means older infrastructure. Clay sewer laterals and 1920s electrical services are common, and both can turn into real line items on an ADU budget.
- Historic districts review exterior changes visible from the street
- Older sewer laterals frequently need upsizing for a second unit
- Mature trees are protected and affect where a unit can go
- The city publishes its own ADU information and fee schedule
Local ordinances, fees and plan availability change faster than any website. We confirm the current Pasadena requirements against your specific parcel before anything is drawn, and that check costs you nothing.
What it costs
| What | Typical Los Angeles range | Notes |
|---|---|---|
| Junior ADU, inside the house | $60,000 to $120,000 | Up to 500 sq ft |
| Garage conversion | $120,000 to $150,000 | 350 to 400 sq ft |
| Detached ADU, 600 to 800 sq ft | $200,000 to $250,000 | Standard finishes |
| Detached ADU, 1,000 to 1,200 sq ft | $300,000 to $350,000 | Larger units |
Work out your own number. The ADU cost calculator gives you a line-item range for your lot and unit type in under a minute.
Los Angeles County figures, reviewed 2026-10-29 by America General Contractors, California contractor licence CSLB 1083262. Planning ranges, not a quote, and not legal advice. We confirm the current rules for your parcel before anything is drawn.
Questions
Can Pasadena refuse my ADU?
Not on a standard unit meeting the state's objective standards. Pasadena applies its own design standards and fees, and reviews the site-specific parts, but it cannot refuse an ADU that meets state law. Hillside, fire-zone and historic conditions add requirements rather than a veto.
How long does an ADU permit take in Pasadena?
State law gives the city 60 days to decide a complete application, plus 15 business days to confirm completeness. Real timelines run two to four months once correction rounds are counted. A pre-approved standard plan, where the city offers one and it fits your lot, is far faster.
Do I need to live on the property?
Not for a full ADU. That requirement was removed permanently by state law. For a junior ADU it can still apply where the junior unit shares a bathroom with the main house.
Can I rent it short term?
Generally no. ADU short-term rental is restricted across the region, and junior ADU rentals must run longer than 30 days under state law.
Do you build in Pasadena?
Yes. We are a licensed California general contractor, CSLB 1083262, working across all of Los Angeles County, and we handle the drawings, the permit and the build.
Related reading
- Can I build an ADU on my property in Los Angeles?
- What are the ADU setback and height rules in Los Angeles?
- What permits do I need for an ADU in Los Angeles?
- What is a junior ADU (JADU)?
- ADU Cost Per Square Foot in Los Angeles
- Garage Conversion Cost in Los Angeles
- Does an ADU Raise Your Property Taxes?
- Pre-Approved ADU Plans in Los Angeles
