Permit guides

ADU Permits in Corte Madera: a Homeowner's Guide

A small Marin town with its own ADU ordinance, pre-approved plans, and extra attention on wildfire and flood zones. Here's how the permit works.

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

Who handles your permit

Permits run through the Community Development Department, Building Division — Town Hall at 300 Tamalpais Drive, Corte Madera, CA 94925 (plcounter@cortemadera.gov). Interior conversions that qualify as statewide-exempt ADUs skip the separate ADU permit and go straight to a building permit application, with the Town's ADU checklist filed to Planning at the same time.

What you can build

California state law sets the baseline:

1,200 sq ftMax for a detached ADU

50% / 1,200Max for an attached ADU (50% of the main home, up to 1,200 sq ft)

500 sq ftMax for a Junior ADU, carved from existing space

16 ftHeight limit for most detached ADUs (18 ft near major transit or above a garage)

4 ftMinimum rear and side setbacks for detached ADUs

1 + 1One ADU plus one JADU allowed per single-family lot

Two local twists: attached ADUs and detached units over 800 square feet get a 10-day courtesy notice mailed to property owners within 300 feet — no hearing, but neighbors are informed. And every JADU needs a recorded deed restriction (no separate sale, no rentals under 30 days) before the building permit issues.

Pre-approved plans, if your lot qualifies

The Town publishes pre-approved detached ADU plans with a site-specific checklist: cover sheet, owner and APN details, zoning, the Town's assigned plan number, and any hazard-zone designation. It's a solid shortcut — but read the hazard designation carefully. The Town enforces wildfire-hardened construction rules in its designated WUI fire areas.

Fire and flood maps decide a lot here. Check your parcel against the Town's WUI fire-area map and flood zones before committing to a plan — they drive materials, elevation, and review requirements.

What goes into the submittal

Site plan with placement, setbacks, and lot coverage; floor plans and exterior elevations.
Foundation and framing details, structural calculations, Title 24 energy forms.
Electrical, plumbing, and mechanical layouts plus utility connection plans.
The Town's ADU checklist to Planning (or the JADU checklist with the recorded deed restriction).

Where applications usually get stuck

WUI fire areas. In designated zones, ignition-resistant materials and fire-hardened details apply to new construction — plan for them up front, not at correction time.
Flood zones. Low-lying properties near the bay and the Lucky Drive corridor sit in flood zones; elevation and floodplain documentation can be the long pole.
The fire marshal's call on setbacks. For smaller and exempt units, side and rear setbacks must satisfy fire safety as determined by the Fire Marshal — a judgment call, not a table lookup.
Multiple plan sets. The Town's guidelines call for five complete plan sets plus two sets of supporting information — incomplete or mixed sets bounce back.

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