Permit guides

ADU Permits in Fremont: a Homeowner's Guide

Fremont keeps a library of pre-approved ADU designs — the fastest way through its review. Here's the full picture.

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

Who handles your permit

ADU permits in Fremont are handled by the Community Development Department at the Development Services Center (39550 Liberty Street), through Planning and Building Permit Services — online or in person. Review is ministerial: no hearings, no discretionary review. A pre-application meeting with planners is strongly recommended, especially for tricky lots.

What you can build

Fremont's key numbers:

1,200 sq ftMax for a detached ADU

16–20 ftHeight: 16 ft base, up to 20 ft with matching roof pitch near transit

4 ftMinimum rear and side setbacks

1 + 1One ADU plus one Junior ADU per single-family lot

Pre-approvedCity library of pre-cleared ADU designs

60 daysDeadline to act on a complete application

Every ADU gets a separate address. Short-term rentals under 30 days are not allowed. AB 2533 legalization procedures apply to pre-2020 unpermitted units.

The pre-approved plan library

Fremont maintains a library of pre-approved ADU designs that already satisfy local zoning and building code. Structural and design review is largely pre-cleared, so choosing one cuts plan-check time and back-and-forth considerably. You still need a site-specific permit — placement, utilities, and foundation are reviewed for your lot.

The cost item to watch in Fremont is utilities: water and sewer connections for ADUs often require separate meters, which commonly run $5,000–$10,000 depending on proximity to existing lines. Confirm with the water district early.

Pre-approved + pre-app meeting. The library plus a pre-application meeting with Planning is the lowest-friction path in Fremont.

What goes into the submittal

A complete Fremont submittal includes:

Site plan, floor plan, elevations, and utility connection details
Structural calculations and Title 24 energy compliance
Pre-application meeting notes (recommended, especially for corner lots)
Separate address request for the ADU
For remodels adding an attached ADU: permits for both the ADU and the main-house work

Where applications usually get stuck

Separate meter costs. $5,000–$10,000 for water/sewer meters surprises a lot of budgets.
Corner lots. Visibility and sight-distance requirements can force civil engineering or survey work.
Flood zones. Additional height may be required to meet elevation requirements.
Remodel-plus-ADU. An attached ADU as part of a remodel needs two permits, not one.

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