Custom ADUs built across the Bay Area — from studios to full 3-bedroom homes, designed and built by one dedicated team.
We design and build custom ADUs across the Bay Area, from studios to full 3-bedroom homes — each one tailored to your lot and built to add real rental income and lasting value to your property. Explore our models below.
Every model comes in two styles — Modern and Farmhouse — with the same floor plan inside. These are starting points, fully customizable to your lot.
Starting from $165,000
Our most efficient unit. An open studio layout with a full kitchen and bath — ideal as a rental, home office, or guest suite. Small footprint, maximum function.
Starting from $235,000
A true one-bedroom home with a defined bedroom, full kitchen, and living space, plus French doors to the backyard. Stays under 500 sq ft to simplify permitting. A strong rental performer.
Starting from $300,000
Two bedrooms in a smart, livable footprint. Open living-kitchen-dining with French doors to the yard. The sweet spot for families who want two bedrooms without going full-size.
Starting from $372,000
Two bedrooms, two full baths including an ensuite, with French doors to the backyard. Enough room to live comfortably long-term. A favorite for multigenerational families.
Starting from $450,000
A full three-bedroom home. Proper family layout with two baths, open great room, and real separation between primary and secondary bedrooms. This lives like a house, not an add-on.
Starting from $540,000
Our largest, most complete model. Three bedrooms, two baths, a primary suite with ensuite and walk-in closet, and French doors from the primary bedroom to a private patio. A standalone home in every sense.
Your ADU should look like it belongs on your property. That's why every California Bay Builders model comes in two design styles — the same floor plan inside, two completely different looks outside.
Which style fits best depends on your existing home and your city’s design guidelines — and we’ll help you choose during design. Your ADU, your style.
An ADU — Accessory Dwelling Unit — is a second, self-contained home on the same lot as your primary residence. It has its own kitchen, bathroom, and entrance. Homeowners use them as rental units, in-law suites, home offices, guest houses, or a place for grown kids to land.
Across the Bay Area, ADUs have become one of the most valuable additions a homeowner can make — both for the strong rental income they generate and the resale value they add to your property.
This is the difference that matters. Prefab companies build a standardized box in a factory and drop it on your lot — whether it fits your property or not. We design and build each ADU on-site, tailored to your lot, your existing home, and how you actually plan to live in it. You’re not choosing from a catalog of boxes — you’re getting a home designed around your property.
Here’s the full California Bay Builders lineup at a glance. Every price is a starting point — the final number depends on your lot, your finishes, and your site conditions, and it comes to you as a detailed proposal before you commit.
| Model | Configuration | Starting From |
|---|---|---|
| 350 sq ft | Studio, 1 Bath | $165,000 |
| 499 sq ft | 1 Bed / 1 Bath | $235,000 |
| 650 sq ft | 2 Bed / 1 Bath | $300,000 |
| 800 sq ft | 2 Bed / 2 Bath | $372,000 |
| 1,000 sq ft | 3 Bed / 2 Bath | $450,000 |
| 1,200 sq ft | 3 Bed / 2 Bath | $540,000 |
Straight talk on pricing — because this is where most Bay Area homeowners get burned by other builders. At California Bay Builders & Remodeling, our “starting from” prices include far more than just the build. Here’s exactly what you get, and what’s priced separately — no surprises.
You’re never on your own for finishes. Through our trusted showroom partners across the Bay Area, we’ll help you select every finish material — flooring, cabinets, countertops, tile, and fixtures — and have it delivered directly to your project. All the choice, none of the hassle.
Every item is broken out in a line-item proposal before you sign anything. You’ll know exactly what you’re paying for across the Bay Area — the “no surprises on the invoice” promise, in writing, before a single wall goes up.
Permit fees go straight to your city — we never mark them up or take a cut. They're separate from our price because every jurisdiction sets its own schedule, and the number depends on your city, your ADU size, and your lot. Here's what Bay Area homeowners are typically paying in 2026:
Under California law, ADUs under 750 square feet are exempt from impact fees — including school and parkland fees. Those alone can run $10,000 to $30,000 on a larger unit. Our 350, 499, and 650 sq ft models all stay under that threshold, which is one reason they perform so well on cost per rentable square foot. If you're weighing a 650 against an 800, this belongs in the conversation.
The East Bay and Tri-Valley are generally the most affordable jurisdictions in the region for ADU permitting. San Jose is moderate and one of the more ADU-friendly big cities, with pre-approved plan options that shorten review. Peninsula cities like Palo Alto and Menlo Park sit at the high end on both fees and review layers. San Francisco carries the highest plan check and utility connection costs plus the longest timelines — worth building into your schedule as well as your budget.
These ranges reflect typical 2026 Bay Area figures and are provided as a planning guide only. Actual permit and impact fees are set by your city, county, and local jurisdiction — including school and water districts — and vary based on your ADU square footage, lot conditions, zoning, and site-specific requirements. Two identical ADUs on different streets can carry different fees. During your free consultation we'll pull the current fee schedule for your specific address so you're budgeting from real numbers, not estimates.
For a lot of Bay Area homeowners, this is the whole reason to build. An ADU isn’t just extra space — it’s an income-producing asset on land you already own.
In the San Jose area, a studio ADU rents for roughly $2,200–$2,400 per month, a 1-bedroom for $2,500–$2,700, a 2-bedroom for around $3,300–$3,400, and a 3-bedroom for $3,500–$3,700 per month. That’s real income against a property you already own — often enough to cover a significant chunk of your financing, sometimes more.
And the returns don’t stop at rent. A well-built ADU adds lasting resale value — you’re not just buying a rental, you’re increasing what your entire property is worth. Two returns from one build.
|
$2,200–$2,400
Studio / mo
|
$2,500–$2,700
1-bedroom / mo
|
$3,300–$3,400
2-bedroom / mo
|
$3,500–$3,700
3-bedroom / mo
|
From first call to final clean-up, here’s exactly how California Bay Builders & Remodeling brings your Bay Area ADU to life.
We visit your property, talk through what you want, and tell you honestly what’s possible on your lot. No cost, no obligation.
Pick one of our ADU packages, and we get to work on the design, planning, and permit drawings — tailored to your lot and your existing home.
While permits are in process, we don’t just wait around. We connect you with our trusted showroom partners and designers to help you select your finish materials — and they deliver everything to your project exactly when we need it.
Before we break ground, we set up the site right: privacy fencing, a portable restroom for our crew, and a dumpster. We also walk your property with you first to see if we can save any plants or landscaping worth keeping.
Construction begins. Every phase is signed off by a city inspection, so the work is done to code and verified at each stage.
When the build is complete, we bring in a professional crew for a full clean — inside and out. Then we walk the finished ADU with you. Congratulations: you’ve got a brand-new ADU and a new stream of passive income.
At California Bay Builders & Remodeling, we build by the book. Every time.
California has opened up ADU laws significantly in recent years, which is good news for homeowners — state ADU law now guarantees a path to approval for qualifying units, and every city must review a complete application within 60 days. ADUs have become a major part of Bay Area housing — accounting for 13.4% of the region’s housing permits. But ADU permits and regulations still have to be done right, and every city in the Bay Area has its own requirements. We handle the entire ADU permit process for you: plans, submissions, city approvals, and inspections, start to finish.
The statewide framework is defined in California Government Code §65852.2, and recent legislation like SB 897 and SB 1033 keeps expanding heights, sizes, and approval rights in homeowners’ favor. Each Bay Area city layers its own size limits, setbacks, and design rules on top — and because these requirements shift city to city and change often, we stay current on all of them so you don’t have to.
Setbacks and placement. Across California, ADUs require a minimum 4-foot setback from side and rear property lines, with detached units typically needing a few feet of separation from your main home. If you’re converting existing space — like a garage — or rebuilding on the same footprint, those setback rules generally don’t apply at all. Exact placement, height limits, and coverage depend on your lot and your city, which is why we assess your specific property before designing anything.
We won’t build without permits — not because we love paperwork, but because an unpermitted ADU can’t be legally rented, can tank a home sale, and can force expensive tear-outs down the line. With California Bay Builders & Remodeling, your ADU is permitted, inspected, and done right the first time.
Official ADU Sources:
California HCD — Accessory Dwelling Units
California HCD — ADU Handbook (2025)
California Government Code §65852.2 — State ADU Law
California Government Code §66300 — Housing Crisis Act
California Senate Bill 897 (2022)
California Senate Bill 1033 (2024)
Bay Area Council Economic Institute — ADU Permit Analysis
Permit timelines vary by city, and most ADU builds run 4 to 5 months of construction once approved. During your consultation, California Bay Builders & Remodeling will give you a realistic schedule for your specific project.
Most homeowners don’t have hundreds of thousands sitting in the bank — and you don’t need to in order to build an ADU in the Bay Area.
The problem with traditional financing is the equity wall: standard loans only lend against what your home is worth today, not what it’ll be worth after your project is complete. That’s why California Bay Builders & Remodeling partners with RenoFi.
A RenoFi HELOC lends against your home’s after-renovation value — what your property will be worth once the work is done — so you can access far more than a traditional loan allows. And it’s not just for ADUs: use it for your ADU, a kitchen remodel, a bathroom remodel, or a full home remodel.
Want to know if you’re eligible? Contact us and we’ll run your personalized financing estimate — free, no obligation.
You deal directly with the people who actually build your ADU — the same team from your first conversation to your final walkthrough.
You’re not a job number. Our team treats your ADU like it’s going in our own backyard — with the attention, communication, and pride your project deserves.
One dedicated point of contact from day one to final walkthrough. You always know exactly who to call and exactly where your project stands.
Design, plans, permits, finishes, and construction — all handled under one roof. No juggling separate architects, designers, and subs. Everything in one place.
Quality materials and real craftsmanship on every ADU. We build to a standard that looks great the day it’s done and holds up beautifully for years.
We design and build on your lot, around your existing home — a true custom ADU, not a factory box dropped on your property.
A detailed, line-item proposal before you sign. You’ll always know exactly what you’re paying for and where your investment goes.
123 five-star reviews on Houzz, 5-star Google ratings, and four Best of Houzz Service awards — fully licensed, bonded, and insured (CSLB #1130783).
Not necessarily. ADUs fit a range of lot sizes, from a compact 350 sq ft studio to a full 1,200 sq ft three-bedroom home. Setback and coverage rules vary by city, but California’s ADU-friendly laws have made it possible on far more Bay Area properties than most homeowners expect. During your free consultation, California Bay Builders & Remodeling will walk your lot and tell you honestly what fits.
Most full ADU builds run 4 to 5 months of construction once permits are approved. City permit approval typically takes 40–60 days in the Bay Area, or as little as 7–10 business days with expedited approval. California Bay Builders & Remodeling handles the entire permit process for you from start to finish.
City approval typically takes 40–60 days. In recent years, Bay Area counties have become far more efficient and are actively encouraging homeowners to build ADUs in response to California’s housing shortage. Some counties offer expedited approval for an additional fee, which can bring it down to 7–10 business days. We’ll advise whether expediting makes sense for your project.
The CalHFA grant program that once offered up to $40,000 ended in 2023 and is no longer available. But you don’t need a grant to make an ADU affordable — a RenoFi HELOC lets you borrow against your home’s after-renovation value, and we’ll generate a personalized estimate for your project.
In most cases, no — under current ADU regulations, a detached ADU is typically assigned its own separate address or unit designation rather than sharing your home’s address. This is part of what makes it a true independent rentable dwelling. Exact rules vary by city, so California Bay Builders & Remodeling will confirm how it works for your property during permitting.
Detached is a standalone unit. Attached shares a wall with your main home. A garage conversion turns your existing garage into a livable unit. A Junior ADU (JADU) is a smaller unit up to 500 sq ft built within your home’s existing walls. We build all four across the Bay Area.
Custom. California Bay Builders & Remodeling is a design-build contractor — our models are starting points, fully customizable to your lot and home. Unlike prefab companies that drop a standardized box on your property, we design and build each ADU on-site. You also choose between two styles: Modern or Farmhouse.
We partner with RenoFi, which finances against your home’s after-renovation value — so you can access far more than a traditional home equity loan allows. It works for ADUs, kitchens, baths, and whole-home remodels. We’ll generate a personalized estimate showing your borrowing power and estimated monthly payment.
Yes — and many of our clients do. In the San Jose area, ADU rents range from around $2,200–$2,400/month for a studio up to $3,500–$3,700/month for a three-bedroom. An ADU also increases your overall property value — two returns from one build.
Your design package (3D design with your selected finishes), full blueprint plans and elevations, Title 24 energy calculations, structural engineering, and the labor and rough materials for the build. Permits, finish materials, appliances, soil reports, fire sprinklers, and site-specific work are priced separately, delivered with help from our showroom partners.
If you’ve got the lot, California Bay Builders & Remodeling can build the ADU — designed around your property, managed by a dedicated team, and backed by our 4-year workmanship warranty. The consultation is free and there’s no obligation. We’ll tell you honestly what’s possible and what it’ll cost.
