ADU in St. Helena, CA

Plan check fee: $500 to $2,000 depending on project complexity
Building permit fee: $3,000 to $8,000 based on valuation
School impact fees: Waived for ADUs under 750 square feet per state law
Utility connection fees: $2,000 to $6,000 depending on distance from main lines

St. Helena ADU builder serving Napa County. Architect-led design-build for detached ADUs, garage conversions, and JADUs. CSLB #1078806. Free on-site estimate.