ADUs built to earn.
Collect rent every month
Turn your backyard into monthly income. From first call to move-in ready in as little as 4 months. We handle design, permits, and construction — you collect the rent.
Check local requirements and estimated project cost
Licensed builder · Our own factory in Lathrop, CA
Real homes we build, start to finish
One team, one price
No hidden fees from start to finish
Financing available
HELOC, ADU loans, and cash options
Delivered in a day
Built in our factory, installed in 1 week
Move-in ready
Kitchen, bath, utilities — all done
One ADU, different uses
All modelsGenerate passive income
Turn unused backyard space into a source of monthly rental income
Keep family close
Create a private home for parents, adult children, or visiting family — steps away and far less than the alternatives
Boost your home's value
The next owner isn't just buying a house. They're buying the rent that comes with it.
Rental income calculator
What could an ADU pay for?
Your city, your home — your monthly income.
Rent is the median asking rent for this unit size in your city (nearest tracked city if we don't track yours). Loan: typical HELOC — 8.5%, 20 years, 10% down. We set aside 5% of rent for vacancy & upkeep. Estimates only; your real numbers come with a free lot check.
A 1 Bedroom ADU in San Jose
All-in $214,900 −30% launchYou keep every month
Rent $2,750 − loan & upkeep $1,816
That's
to see how much of it your tenant covers
for college, savings or travel — before rent increases
Estimate only.
Models
View All ModelsExplore models & styles
Your ADU, your way
Pick the size, the facade and the finishes. See it instantly, get one fixed price.
FACADE Natural cedar
INTERIOR Classic white
Illustrative styles · finishes confirmed in your written quote
Ways to finance your ADU
Use your home's equity
HELOC or cash-out refinance. Borrow against what you already own.
ADU construction loan
Lenders that specialize in California ADUs. Some lend on your home's value after the ADU is built.
Find your way to pay in 2 minutes
6 quick questions point you to the right loan.
How it works
Check your lot
See what you can build on your property
Pick a model
Find the right size and layout for your needs
Plan your site
We confirm site needs, costs, and next steps
Handle permits
We coordinate the required permits and approvals
Build your home
We build your ADU while permits are in review
Deliver & install
Your finished ADU is delivered and installed on site
Connect & complete
We finish utility connections and final site work
Achieve your goal
Keep your family closer or get your first income
Have questions about the process?
Compared with building on site
Modern in-house manufacturing
Visit our Lathrop factory and see homes, materials, and building process up close
Book a TourWhere we build
Built in Lathrop. Installed across California.
One factory in Lathrop, one all-in price statewide. Your ADU arrives on a truck and is installed in days.
Common questions
How much does it actually cost?
Our 1 Bedroom ADU — 480 sq ft — is $214,900 all in. That includes the foundation, permits, delivery, the crane, utility hook-ups and final inspection. It is not a starting price.
See the full breakdownDoes it look like a shipping container inside?
No. Full-size kitchen, a real shower rather than a stall, and standard ceiling height. But don't take our word for it — the factory is in Lathrop and you're welcome to walk through one.
See the photosHow long does it take?
Four to six months from signing to keys. Your permit is under review while we're already building the home — that's why it isn't the twelve to eighteen months that building on site takes.
Will a bank finance it?
Yes. Our plans carry California HCD approval, which makes the home real property — appraised and financed like an ordinary house, not as a manufactured home. Most owners borrow against the equity in the house they already own.
FinancingWill my property taxes go up?
Only on what you add. California reassesses new construction, not the home you already own — your existing assessment stays as it is. Your county assessor can confirm the specifics for your address.
Do my neighbors have to approve it?
No. California requires your city to approve a qualifying ADU ministerially — no public hearing, no neighbor sign-off, and no refusal based on how it looks.
What if my lot doesn't work?
Then we'll tell you before you've spent anything. Not every backyard can take one, and crane access is usually the reason. The check is free and takes three days.
Ready to start?
Start with Bay Modular
Submit your information and our team will get back
to you about next steps