ADU permit guide for Modesto, California
Stanislaus County, CaliforniaReviewed August 28, 2026
Use this page for early ADU permit planning in Modesto. A verified local process guide is not available yet, so confirm every step and fee with the city before you submit.
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Permit fee planning by size
GetYourPermit research · 5 published reference lines
| ADU size | Researched range |
|---|---|
| 600 sq ft | $5,301 – $10,732 |
| 800 sq ftimpact-fee band | $9,048 – $21,378 |
| 1,000 sq ft | $9,925 – $23,604 |
| 1,200 sq ft | $10,906 – $26,054 |
Getting the permit
We have not written Modesto’s permit guide yet. The official sources below are the right place to start.
View official permit starting points