Yuliia Bortna 10/8/26 Yuliia Bortna 10/8/26

Sunnyvale ADU Guide (2026): Rules, Fees, and Building a Backyard ADU

Sunnyvale rewrote its ADU rules in 2025 and updated them in July 2026: up to 1,000 sq ft, no parking, and a building-permit-only path up to 800 sq ft. Here's what you can build and what the city charges.

Sunnyvale ADU Guide (2026): Rules, Fees, and Building a Backyard ADU

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Here’s the whole process on one page.

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