What to Budget for building an ADU/ JADU

By Lisa Bibbee | Coldwell Banker Realty
831.295.0065 | homebylisab.com

Thinking about adding an ADU or JADU unit in Santa Cruz County? This guide breaks down the key differences, local regulations, and permitting requirements you need to know before building or buying. Learn how each option impacts property value, rental potential, and long-term flexibility, plus where to find official Santa Cruz County and City guidelines to get started with confidence.

Permit costs for an ADU in Santa Cruz County vary significantly, but expect $10,000 – $20,000+ for planning/building fees, with smaller ADUs (<750 sq ft) getting waivers on impact fees and planning fees, saving thousands compared to larger units. Other costs include $10k-$20k for utility connections, $5k-$8k for PG&E, and $15k-$35k for plans/engineering, totaling potentially $40k-$80k in soft costs alone, plus construction.

Key Factors Influencing Cost

Size Matters: Units under 750 sq ft get major fee breaks (impact, planning, affordable housing fees).
Type of ADU: Conversions (garage/attic) often have lower engineering/soil report costs than new, detached builds.
Location: Proximity to water/sewer lines (especially in Soquel Creek Water District) impacts utility hookup fees.
Agency Fees: Costs for Planning & Building Depts, plus potential county/city specific fees.

Typical Fee Breakdown (Estimates)

Planning & Building Dept Fees: $10,000 – $20,000+ (lower for small ADUs).
Utility Connections (Water/Sewer/Fire): $10,000 – $20,000 (more if new services needed).
PG&E/Electric: $5,000 – $8,000 (depends on panel/distance).
Design & Engineering (Plans, Soils, Energy): $15,000 – $35,000.

Where to Get Specifics

Use the Santa Cruz County ADU Fee, Cost, and Cash Flow Estimator tool on the county’s website.
Review the Basic Requirements page on the Planning Department site.

📌 Helpful Links

📍 Estimate ADU Fees and Costs

https://cdi.santacruzcountyca.gov/Planning/Housing/ADU/FeeEstimator.aspx

📍 Residential Fee Estimator

https://cdi.santacruzcountyca.gov/UPC/BuildingPermitsSafety/FeesPayments/ResidentialBuildingPermitFeeEstimator.aspx

📍 For questions related to planning and zoning

Planning.ZoningInfo@santacruzcountyca.gov or call (831) 454-2130

Understanding the differences between ADUs & JADUs units is essential when buying, building, or selling in Santa Cruz County. With evolving state laws, coastal regulations, and local permitting requirements, these secondary units can significantly impact property value, rental potential, and long-term flexibility. Whether you’re considering adding an accessory unit or evaluating a property that already has one, having the right guidance makes all the difference. If you’re exploring your options anywhere in Santa Cruz County, I’m always happy to help you navigate the process with clarity and confidence so you can make the most of your coastal investment.

Love Where You Live.

Call/Text: 831.295.0065
Website: homebylisab.com
Lisa Bibbee | Coldwell Banker Realty | CalDRE#02348001

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