Pasadena ADU: Regulations, Costs & Permits

On a single-family lot, Pasadena allows one newly built ADU (attached or detached), one ADU converted from existing space, and one JADU. The 2026 amendment removed an earlier cap the state objected to, which had limited how many state-protected units a lot could have.

• Exemption ADUs: state-protected units, meaning a new ADU up to 800 sq ft with 4 ft front, side, and rear setbacks, a conversion of existing space (plus up to 150 sq ft for access), or a JADU. They skip the zone's floor area and lot coverage limits and need no parking.
• Larger ADUs: detached units up to 1,200 sq ft, and attached units up to 850 sq ft (studio or one-bedroom) or 1,000 sq ft (more bedrooms). These must meet the zone's encroachment plane, floor area, lot coverage, and setbacks, and anything over 800 sq ft must meet the front-yard setback.
• Minimum size: 150 sq ft. You can measure floor area under the city code or the Building Code, whichever works better for your plan.

• Detached height: generally 18 ft and two stories. It drops to 16 ft in Hillside Overlay Districts, in Landmark or Historic Districts where the ADU is visible from the street, and for exemption ADUs in the front-yard setback.
• Attached height: up to 25 ft (or the zone limit if lower) and two stories.
• Setbacks: 4 ft side and rear. Larger ADUs need 6 ft eave-to-eave separation from other buildings.
• Second-story windows: on larger ADUs, no new second-story windows along interior side or rear lot lines where the setback is under 5 ft, except required clerestories.
• Street visibility: entrances and exterior stairs of attached ADUs on single-family lots shouldn't be visible from the street unless that would make the unit impossible.

• Hillside Overlay Districts: on lots served by streets 26 ft wide or narrower, new ADUs are capped at 800 sq ft. Elsewhere in the overlay, detached ADUs top out at 1,000 sq ft and 16 ft.
• Historic properties: on designated properties and in Landmark or Historic Districts, larger ADUs shouldn't be visible from the street, visible detached units are limited to 16 ft, and no parking is required.
• Fire safety at plan check: the site plan must say whether the lot is in a high fire hazard zone, where a landscape and fuel modification plan follows as a deferred submittal. Expect a Pasadena Water and Power fire-flow report dated within 6 months, a hydrant within 400 ft of every exterior wall (600 ft with sprinklers), and the ADU within 150 ft of fire access. The ADU needs sprinklers if the house has them.
• Trees: plans need a tree inventory and tree protection plan, with every tree shown on the site plan.

• Extra standard plans: owners of homes red-tagged in the Eaton Fire can use four free city-designed ADU plans from 400 to 750 sq ft. Other owners currently have one, a 374 sq ft studio.
• The fee waiver doesn't cover ADUs: Pasadena's Fire Rebuild Fee Waiver covers like-for-like rebuilds of the home, but not new structures that didn't exist before the fire, including rebuilding a garage as an ADU.
• Free consultations: Planning offers free 30-minute virtual ADU consultations on Mondays, Tuesdays, and Thursdays, 1 to 5 p.m.

• Ministerial approval: ADUs are approved by staff within state time limits, with no hearing.
• Online submittal: through the city's Customer Self-Service portal at cityofpasadena.net/mypermits.
• Turnaround: the city has published 3 to 4 weeks for the first plan check and about 2 weeks for resubmittals.
• Standard plans: free, detached-only, and any change triggers full plan review. You still need a site plan, tree plan, and hold-harmless agreement.

• 900 sq ft or less: no Residential Impact Fee, and 25% off the construction tax and permit fees. That's a higher threshold than the state's 750 sq ft.
• Standard plan ADUs: 50% off plan check, plus no Residential Impact Fee or construction tax.
• Housing Agreement ADUs: sign a 7-year ADU Landlord Agreement or 120% AMI affordability covenant for 50% off plan check and no impact fee or construction tax, at any size.
• Over 900 sq ft: Residential Impact Fees apply in proportion to size.
• Construction and demolition deposit: reduced to $1,000 for all ADUs.

• Parking: one space for a larger ADU, waived for exemption ADUs, lots within half a mile of transit, conversions, historic districts, and lots near car share. The ADU shares the existing driveway, and a second driveway is only allowed off an alley.
• Rentals: longer than 30 days for ADUs and JADUs created since 2017.
• Selling: ADUs can't be sold separately, except by a qualified nonprofit under state law.
• JADUs: up to 500 sq ft inside the house or attached garage. If it shares a bathroom with the house, the owner must live on site, with a covenant recorded before permit.

How big can a detached ADU be in Pasadena?

Up to 1,200 sq ft on most single-family lots, with the zone's setbacks and lot coverage applying above 800 sq ft. In Hillside Overlay Districts the cap is 1,000 sq ft, or 800 sq ft on narrow streets.

What fees does Pasadena waive for ADUs?

ADUs of 900 sq ft or less skip the Residential Impact Fee and get 25% off the construction tax and permit fees. Standard plan and Housing Agreement ADUs get bigger breaks.

Does Pasadena's fire rebuild fee waiver cover an ADU?

No. It covers like-for-like rebuilds of the home. A new ADU, including rebuilding a garage as an ADU, pays regular fees, though red-tagged owners can use four free city ADU plans.

How long does ADU plan check take in Pasadena?

The city has published 3 to 4 weeks for the first review and about 2 weeks for each resubmittal.

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