Can I Build an ADU in Pasadena?

Yes — by right

ADUs and JADUs are allowed by right in all residential and mixed-use zones; ministerial approval, no hearing.

1 ADU + 1 JADU

At least one ADU and one JADU per single-family lot (a conversion ADU may also be possible).

Conversion ADUs (≥1, up to 25% of existing units) + up to 2 detached

Pasadena caps detached new-construction/conversion ADUs on a multifamily lot at 2 (the state floor allows up to 8), alongside interior-conversion ADUs of up to 25% of existing units.

Allowed

Up to 500 sq ft, within the walls of an existing single-family home (single-family lots only).

1,200 sq ft

A non-exemption detached ADU may reach 1,200 sq ft. The 800 sq ft / 16-ft / 4-ft-setback 'exemption' ADU must be allowed by right regardless of underlying-zone standards.

Non-exemption attached ADU up to 850 sq ft (studio/1-bedroom) or 1,000 sq ft (2+ bedrooms); the 800 sq ft 'exemption' ADU is always allowed

800 sq ft

An 800 sq ft ADU must be allowed regardless of FAR/lot-coverage caps; a city also cannot cap an attached ADU below 850 sq ft (1,000 for 2+ bedrooms).

500 sq ft

16 ft

16 ft baseline; cities must allow 18 ft within ½ mi of a major transit stop or where the primary dwelling is two-story, and 20 ft on a lot with a multistory multifamily building.

4 ft

A city cannot require more than 4 ft side or rear setback; conversions of existing structures are exempt.

4 ft

No front setback may block the mandatory 800 sq ft / 16-ft / 4-ft-setback ADU; otherwise per base zone

6 ft

A non-exemption new-construction ADU must maintain a minimum 6-ft building separation (eave to eave) from any other structure on the site (excluding walls and fences). The 800 sq ft 'exemption' ADU is not subject to this; state law sets no separation.

Up to 1 space

At most 1 space per ADU (or per bedroom, whichever is less) — and waived in the common cases below.

Yes — no parking required near transit & for conversions

No parking may be required within ½ mi walking distance of transit, in a historic district, for an ADU within an existing structure, within one block of car-share, or in certain permit-parking areas.

Not required

When a garage/carport is demolished or converted to build an ADU, replacement parking cannot be required.

Ministerial (by right)

No public hearing or discretionary design review for a qualifying ADU.

60 days

The agency must act within 60 days of a complete application — and the ADU is deemed approved if it does not.

Only for a JADU

No owner-occupancy requirement for ADUs (the prior sunset was removed). A JADU may require owner-occupancy, principally where it shares sanitation with the main house.

Waived under 750 sq ft

An ADU of 750 sq ft or less pays no impact fees (the 750 sq ft threshold itself is exempt under § 66311.5); larger ADUs pay fees proportional to the primary dwelling. JADUs (≤ 500 sq ft) are exempt.

Building permit, Ministerial planning review

Pasadena routes ADUs through a ministerial planning review in addition to the building permit — no hearing or discretion, but a planning sign-off the bare state floor does not name.