The Complete Fremont ADU Requirements Guide
If you’re considering building an accessory dwelling unit (ADU) in Fremont, understanding the requirements upfront will make the process easier.
ADUs are secondary housing units—like a backyard cottage, converted garage, or in-law unit—built on the same lot as a primary home. Thanks to statewide ADU laws, cities like Fremont must approve qualifying ADUs in all residential zones. Fremont has updated its local code to comply with state law and offers a clear, ministerial path to approval.
Read on to learn the requirements for building an ADU in Fremont and how Samara can help you get it done.
Fremont ADU regulations at a glance
ADU applications in Fremont require a building permit and a separate address. If you’re adding an attached ADU as part of a remodel, you’ll likely need both a building permit for the ADU and a separate permit for the main residence work. All permits are approved through a simple, by-the-book ministerial process—no hearings or discretionary review.
The city is required to review complete applications within 60 days, and most ADU projects are approved in three to four months.
Size and lot requirements
There is no minimum lot size for building an ADU in Fremont. Maximum size and height vary by type:
- Detached ADUs can be up to 1,200 square feet. The base height limit is 16 feet, or 18 feet if the lot is within half a mile of a major transit stop or includes a multifamily building, and up to 20 feet if the roof pitch matches the main home, as required by state law.
- Attached ADUs can be up to 1,200 square feet or 50% of the main residence’s floor area, whichever is less.
- Junior ADUs (JADUs) must be built entirely within an existing or proposed single-family home and are limited to 500 square feet.
All new ADUs must maintain 4-foot side and rear setbacks. These setbacks do not apply to conversions or rebuilds of existing structures. Additional height may be required in flood zones to meet elevation requirements.
Samara has an ADU for every yard.
Choose from five prefab models.
supersized.
and then some.
Too perfect.
for everything.
Yay big.
Design requirements
Fremont does not require ADUs to match the design or materials of the primary home. ADUs are approved ministerially and are not subject to discretionary design review. However, ADUs on properties listed on a historic register may be subject to additional objective design standards.
Parking requirements
No parking is required for ADUs in Fremont. If a garage or carport is converted to an ADU, no replacement parking is required. JADUs also never require parking.
Zoning eligibility
ADUs are allowed in all Fremont zoning districts that allow residential use, including single-family, multifamily, and mixed-use zones. All ADUs must be located on a lot with an existing or proposed primary home. JADUs are allowed only within existing or proposed single-family homes and must be created within the main residence.
You could keep reading about ADUs.
Or step inside one.
Find a showroom
Number of ADUs allowed
On single-family lots, you can build one detached or attached ADU, plus one JADU within the existing home.
On multifamily lots with an existing residential building, California law now requires Fremont to allow up to eight detached ADUs—or fewer if that would exceed the number of existing units—and interior conversion ADUs totaling up to 25% of the unit count. If the multifamily building is still under construction, up to two detached ADUs are allowed during development.
Streamline your ADU project in Fremont
If you’re looking to build an ADU, Samara makes it easy. We handle everything from permits to installation and even offer our own financing. Call us at 650-420-2607 to schedule a 15-minute consultation and discover how simple adding a Backyard ADU can be.
Sources:
With five prefab models, Samara has an ADU for every yard.
Explore the lineup
You’ve subscribed to Samara updates.