Searching for a trusted ADU Builder Napa Valley? Gerosa Construction is a leading ADU Builder Sonoma County, ADU Builder Marin County, and experienced ADU Contractor Napa County. As a reliable North Bay ADU Builder, we deliver high-quality custom ADUs with expert craftsmanship. Call (707) 363-5923 or visit https://www.gerosaconstruction.com/. Serving Napa, California 94558.