ADU Impact Fees: San Jose vs Sunnyvale

Are San Jose ADU impact fees really $0 for a small unit?

Yes, for new-construction ADUs under 750 sq ft. State law preempts cities from charging impact fees on these units. Permit fees and plan check fees still apply, and the school district may charge separate fees depending on size.

What if my ADU is 800 sq ft - the city's detached cap?

Then it is no longer exempt under the 750 sq ft rule. The city collects impact fees prorated by the ADU's floor area relative to the main house. On a 2,000 sq ft house this works out to roughly 40 percent of the new-house fee schedule.

Are Sunnyvale ADUs charged impact fees?

ADUs under 750 sq ft are exempt from all city impact fees under California Government Code 65852.2(f)(3). This includes Sunnyvale park, traffic, and capital facilities fees as well as school impact fees. ADUs 750 sq ft and larger pay fees proportional to the primary dwelling's size.

What does a Sunnyvale ADU cost to permit?

Permit and plan-check fees typically run $3,000-$6,000 - moderate among Silicon Valley cities. ADUs under 750 sq ft skip all impact fees under state law. ADUs over 750 sq ft pay proportional impact and school fees on top of the permit cost.