Sunnyvale ADU Regulations

• ✓Clear split between streamlined vs MPP pathways depending on ADU type
• ✓Multifamily ADU allowances differ for existing vs proposed MFH
• ✓Pre-approved plan library aimed at faster review
• ✓JADU and conversion categories explicitly enumerated

Attached, detached, conversion, and JADU types. JADU up to 500 sq ft. Detached/attached maxima published on the city ADU page (commonly cited ~1,200 sq ft cap for detached; attached = lesser of 50% primary or cap).

State guarantee: California requires every city to allow at least an 800 sq ft ADU exempt from local lot coverage, FAR, and front-setback rules.

Height baseline: 16 ft for detached, rising to 18 ft within ½ mile of major transit. Attached ADUs follow the primary home, capped at 25 ft.

No additional off-street parking required for qualifying ADUs consistent with state law. Garage conversions typically do not require replacement stalls.

Some ADU types use streamlined ministerial review. Others require a Miscellaneous Planning Permit (MPP) plus building permit. The Permit Center explains which path applies.

State backstop: A complete ADU permit must receive a decision in 60 business days. If the city stalls past 30 business days, AB 253 lets you hire a certified private plan checker to force a 10-business-day decision.

Standard planning/building fee schedules apply. Pre-approved plan library aimed at reducing design cost.

SB 543: No impact fees on ADUs ≤750 sq ft. Above 750 sq ft, fees scale to the ratio of ADU size vs the main home.

Visit the official Sunnyvale ADU page (link in hero) for current eligibility and downloads.

Standard ADUs in Sunnyvale: no owner-occupancy required (made permanent in 2023).

JADUs: limited to 500 sq ft of interior livable space within an existing single-family home. Owner occupancy is required only when sanitation facilities are shared with the main house. JADUs cannot be used as short-term rentals (AB 1154 / SB 543).