Permit guides

ADU Permits in San Rafael: a Homeowner's Guide

San Rafael offers pre-approved ADU plans and fee waivers for smaller units — but hazard maps rule out whole parts of town. Here's the permit process in plain language.

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

Who handles your permit

ADU permits run through the city's Community & Economic Development Department, Building Division. The public counter is on the 3rd floor of City Hall at 1400 5th Avenue. Applications are filed through OpenGov, the city's online portal since February 2026 (it replaced eTRAKiT); building, planning, fire prevention, and code enforcement all route through the same system.

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

One local break: for ADUs under 750 square feet, the city waives impact fees, general plan maintenance and street maintenance fees, and bedroom taxes. Planning fees are folded into the building permit application and based on project valuation.

The city's pre-approved plans

San Rafael publishes pre-approved ADU master plan packages. The application is the same building permit application as any other project, plus the master plan package, a site plan for your parcel, and specs with noise attenuation for outdoor mechanical equipment. The plans may not be altered in any way — change one detail and you're back in full plan check.

Pre-approved plans don't work on every lot. They're limited to parcels outside the Hillside, Wildland Urban Interface (WUI), USGS geologic zones, and tsunami inundation zones. Check the maps for your address before choosing this path.

What goes into the submittal

Site plan showing placement, setbacks, and lot coverage for your parcel.
Floor plans, exterior elevations, foundation and framing details.
Structural calculations and Title 24 energy compliance forms.
MEP layouts and utility connection plans; uploads are unsecured PDFs (75 MB limit).

Where applications usually get stuck

Bigger units can trigger design review. Second units over 800 sq ft or in a two-story detached structure can be routed to environmental and design review at the Planning Commission level — ask Planning early whether your design is reviewed ministerially.
Hillside lots. Slopes over 25% fall under the hillside guidelines: height measured from existing grade, protected natural-state areas, three-for-one tree replacement.
Creeks and wetlands. Keep 25 feet from creeks and the San Rafael Canal, 50 feet from wetlands — verify before placing the unit.
Unpermitted existing units. Legalization follows the same permit and code path as new construction, with inspectors opening walls to verify what's inside.

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