Permit guides

ADU Permits in Danville: a Homeowner's Guide

Danville's free Garden Cottage plans clear review in as little as five days — but three outside agencies get their own say.

Last updated October 2026. Rules change; always confirm current requirements with the city before you build.

Who handles your permit

The Town of Danville Planning Division runs ADU review as a purely ministerial, staff-level process — no hearings. The Building Division checks California building and energy code; the Engineering Division reviews grading where slopes or easements are involved. The town's ADU FAQ walks through the steps plainly.

What you can build

Danville's Garden Cottage fast track:

FREEGarden Cottage permit-ready plans

5 daysExpedited review, non-customized plans

10 daysFirst review for customized plans

800–1,000Typical ministerial size range

16 ftHeight limit for most detached ADUs

4 ftMinimum rear and side setbacks

Garden Cottage plans come in Studio, 1-bed/1-bath, and 2-bed/1.5-bath sizes across Mediterranean, Craftsman, and Contemporary styles.

Free plans — three outside agencies

Danville's Garden Cottage Program offers free, downloadable, permit-ready ADU plans — structural, electrical, and energy pre-checked. Use one unmodified and review can clear in 5 days; customize it and you're on the standard 10-day first-review track.

The critical Danville wrinkle: three outside agencies review ADUs independently — East Bay Municipal Utility District (EBMUD) for water, Central Contra Costa Sanitary District (Central San) for sewer, and the San Ramon Valley Fire Protection District for fire. Their approvals run on separate clocks.

Also note: lot surveys are required if proposed setbacks are under 5 feet, and Danville's many HOAs can't prohibit state-compliant ADUs but may still impose design standards.

Start the agency reviews early. EBMUD, Central San, and the fire district are the long pole in Danville — engage them before you submit to the town.

What goes into the submittal

Danville's steps per the town FAQ:

Optional pre-step: review property requirements and select a Garden Cottage plan
Complete building permit application with all plans and documents
Lot survey if proposed setbacks are under 5 feet
Outside agency approvals: EBMUD, Central San, San Ramon Valley Fire
Ministerial staff review, then building permit issuance

Where applications usually get stuck

Three-agency coordination. EBMUD, Central San, and fire district reviews each add time.
Slope and grading. Hillside lots trigger Engineering Division grading review.
Customized-plan track. Deviating from Garden Cottage plans moves you to the slower review.
HOA design standards. They can't block the ADU, but they can add design requirements.

Not sure where to start? That's the part we do. We look at your property, map the requirements, coordinate the plans and specialists, and manage the submittal and corrections — one point of contact.

Tell us what you need help with.

Not sure where to start? That's what we're here for.

Send your project

Erik — (916) 540-8960 · Vall — (916) 956-8106
office@pcg-engineering.pro