Step 4: How much will it cost?

ADU Example 6

Accessory Dwelling Unit. (2022). California Department of Housing and Community Development.

Total fees will depend on the specific circumstances of your property and the scope of your project.

  • In addition to Plan Check and Permit Issuance fees, ADUs are subject to some – but not all – of the development impact fees and utility connection/capacity fees that primary dwellings are.
  •  No City or County impact fees are charged for ADUs under 750 square feet.
    • If an ADU is 750 square feet or larger, impact fees shall be charged proportionately in relation to the square footage of the ADU to the square footage of the primary dwelling unit.
    • ADUs 800 to 1,000 square feet are charged ADU permit fees and impact fees. 
    • ADUs 1,000 to 1,200 square feet are charged zoning administrator permit fees and impact fees.
  • Check with staff for questions about impact fees.

Will having an ADU increase property taxes? 

  • A reassessment of the property with the ADU would count as an improvement on the property, and as a result would increase property taxes. We recommend that you check with the Yolo County Tax Assessors office regarding the reassessment process (530-666-8135).

Need more information on financing an ADU? 

  • Visit the California Department of Housing and Community Development ADU Page for recommendations.

Approved ADUs 2022-23

All numbers provided are estimates, fees will depend on each project. All estimates are based on ADUs under 750sqft and were not charged impact fees, ADU permit fees, or ZAP fees. Construction cost include building, plumbing, electrical, and mechanical construction costs.
Type of ADU  Square Footage Construction Cost  Building Permit Fees Impact Fees ADU Permit Fees ZAP Fees
Detached 308-749 sqft $80,000-$190,000 $4,200-$5,400 $0 $0 $0
Converted 225-748 sqft $21,450-$112,200 $1,025-$3,025 $0 $0 $0
 Attached 623-745 sqft $149,000-$207,000 $3,900-$4,400 $0 $0 $0