Cost to build accessory dwelling unit — Sunnyvale, CA
Last updated: September 24, 2026
What affects the price
Building an ADU involves variables that shift your total investment. The footprint size and complexity of the architectural design are primary factors. Are you planning a detached unit that requires new utility trenching, or is this a garage conversion that uses existing plumbing? Site accessibility, soil conditions, and your choice of finishes—like luxury flooring versus standard options—also play significant roles. Permitting fees vary widely depending on your local municipality and current zoning requirements. Exact pricing confirmed free on the call.
About this service
The expense of building an ADU varies based on site preparation, whether you need to run new sewer or electrical lines, and the level of interior customization you choose. Larger custom builds naturally require more materials and labor than simpler conversions. We provide exact pricing confirmed free on the call.
Frequently asked in Sunnyvale
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Can I get an ADU built quickly in Sunnyvale?
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What makes a 'best' accessory dwelling unit in Sunnyvale?
What exactly is an accessory dwelling unit?
Also serving nearby: Santa Clara · Burbank · Fremont · San Jose · Hayward
More on this: HUD ADU resources — ADU policy and financing research.
Service area details
Serving all of Sunnyvale — population 151,967; about 6,888 residents per square mile across 22.1 sq mi. ZIP codes covered include 94085, 94086, 94087, 94088, 94089.
Neighborhoods served in Sunnyvale: Cherry Orchard, Lakewood, Ortega Park, Sunnyvale Downtown, West Sunnyvale — and every surrounding area.
Areas we serve
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