As a licensed design-build contractor in San Jose, we bring design, permits, and construction together under one roof — so you work directly with the owners from the first sketch to the final walkthrough, across San Jose and the greater Bay Area.
California Bay Builders & Remodeling is a licensed San Jose design-build general contractor serving homeowners across Santa Clara County, the Peninsula, and the East Bay. From custom ADUs and luxury kitchen and bathroom remodels to room additions and whole-home renovations, we handle design, permits, and construction under one roof — with one team and one point of accountability.
You deal directly with the owner from the first walkthrough to the final punch list. No handoffs, no gaps — just one company that owns your project start to finish, so you always know who's accountable and what comes next.
Custom ADUs and garage conversions — detached, attached, and junior units. Add legal square footage, rental income, or space for family. We handle design, engineering, and city permits, start to finish.
ADUs start at $165,000 for 350 sq ft. An 800 sq ft unit typically starts at $372,000. We build from ready plan sets at 350, 499, 650, 800, 1,000, and 1,200 sq ft — cutting design time and cost. Want a size that isn’t on the list? We’ll draw it custom. Plans are priced separately from construction.
City permit approval runs 40–60 days and varies by jurisdiction — San Jose moves faster than most, while Palo Alto, Los Gatos, and Fremont each have their own rhythm (expedited approval, where available, can take as little as 7–10 business days). Construction takes 4 to 5 months. During your consultation, we’ll give you a realistic schedule for your specific project.
Detached ADU
The most common choice, and the strongest for rental income. Separate entrance, real privacy, and a tenant who never walks through your kitchen.
Attached ADU
Usually the right call when it’s for family. Aging parents or an adult kid get their own space without being across town.
Garage Conversion
The fastest, most affordable route to a rental unit. The structure and foundation are already there.
Why homeowners are building now. California’s housing shortage has pushed cities across the Bay Area to make ADUs dramatically easier to permit — shorter approval timelines, fewer restrictions, and in San Jose, an express permitting lane. Lots that couldn’t support an ADU five years ago often can today. For most homeowners, an ADU is the only way to add real passive income to property they already own.
We build ADUs throughout San Jose, Santa Clara, Sunnyvale, Cupertino, Campbell, Mountain View, Los Gatos, Saratoga, Los Altos, Palo Alto, and Fremont, and across the greater Bay Area.
Layout, cabinetry, countertops, lighting, appliances. From targeted updates to full gut renovations. We handle 3D design, plans, permits, and construction — so you see your kitchen before we build it.
A small kitchen remodel in San Jose typically runs $35,000. A large kitchen lands around $60,000, and a fully custom XL kitchen can reach $80,000. The range depends on size and scope — how much you’re moving, and how far you’re taking the finishes.
Most kitchens take 6–8 weeks. Larger kitchens with more detail run 8–10 weeks.
Yes, it needs a permit
Every kitchen remodel does — because we bring the electrical, mechanical, and plumbing up to current code. If we’re moving walls, it also means footing and framing inspections. We pull the permit and manage the inspections. You don’t chase a plan checker.
You’ll see it before we build it
Every kitchen starts with a 3D design. You walk through the finished space on screen before a single cabinet comes out. Our designer works with you to maximize the layout — not just make it pretty, but make it work.
The finish materials are handled
We work with partner showrooms who already have your design. Walk in, tell them what you like, and they’ll show you cabinets, countertops, and backsplash that fit your kitchen. They coordinate delivery with our schedule directly. You pick what you love. We handle the logistics.
The mistake we see most
Homeowners hire a designer, a cabinet guy, a plumber, and a tile installer separately — and when something goes wrong, every one of them points at the other. Nobody owns it. Weeks disappear. You get one team, one project manager, one point of contact, and one person accountable for the whole thing.
We remodel kitchens throughout San Jose, Santa Clara, Sunnyvale, Cupertino, Campbell, Los Gatos, Mountain View, Palo Alto, and across the greater Bay Area.
Primary baths, guest baths, and full gut renovations. Tile, fixtures, vanities, and layouts that make a small room feel like a retreat.
A small bathroom remodel starts at $23,500. A large bathroom runs around $40,000, and an XL primary suite can reach $60,000.
Most bathrooms take 4–6 weeks. Larger baths with more detail run 5–8 weeks. A full XL primary suite can take up to 10 weeks.
Yes, it needs a permit
Same as a kitchen — we bring electrical, mechanical, and plumbing up to current code. We pull the permit and manage the inspections.
You’ll see it before we build it
Every bathroom starts with a 3D design. Our partner showrooms already have your plan, so when you walk in, they’ll show you tile, fixtures, and vanities that actually fit the space — and they coordinate delivery with our schedule directly.
Waterproofing done properly
It’s behind the tile where nobody sees it — which is exactly why it matters most. We use proper waterproofing systems built to last, so your bathroom stays beautiful and protected for years to come.
Design first, then fixtures
We finalize your design before anything is purchased, so every vanity, fixture, and finish fits the plumbing, the clearances, and the space perfectly. No costly guesswork.
One coordinated team
Tile, plumbing, and glass are all handled by one team on one schedule — so your project moves smoothly from start to finish, on time.
Proper ventilation
We size and install the right ventilation for your Bay Area bathroom, protecting against moisture and mold for the long term. It’s a detail we never skip.
We remodel bathrooms throughout San Jose, Santa Clara, Sunnyvale, Cupertino, Campbell, Los Gatos, Mountain View, Palo Alto, and across the greater Bay Area.
More square footage that matches your existing home — not a bolt-on. In-law suites, primary suite additions, kitchen extensions, and second-story builds. We handle plans, structural engineering, and city permits.
A smaller addition around 350 sq ft starts near $150,000. A larger 800 sq ft addition starts around $400,000. Pricing varies more here than on any other project — every house has different elevation, different soil, and different existing structure, and all three change what the foundation and framing require. These figures are for first-story additions.
Design, structural engineering, and Title 24 run 6–8 weeks. City approval takes 60–90 days. Construction runs 4–5 months.
We do the homework before you invest in drawings
Setbacks, lot coverage, and height limits vary by city — and a design that ignores them gets rejected at plan check, costing you months. We run the full due diligence up front, and our architect and engineer visit your site in person before anything is drawn. We’re not guessing from a satellite photo. The goal is to maximize what your lot will actually allow.
Designing before checking the setbacks
Homeowners pay an architect for a beautiful set of plans, then find out at plan check that the addition can’t legally sit where it’s drawn. Now they’re paying twice.
Assuming the foundation will work
Bay Area soil varies block to block. Expansive clay, a high water table, or a hillside lot can change your foundation cost dramatically — and you don’t find that out from a floor plan.
Building something that looks bolted on
A roofline that doesn’t match, siding that doesn’t align, windows in a different style. It reads as an addition from the street forever, and it costs you at resale.
Underestimating the permit timeline
Sixty to ninety days is normal. Homeowners who plan around a 30-day approval end up living in a construction zone longer than they budgeted for.
Not asking about the second story
If you might go up later, the foundation and framing decisions you make now determine whether that’s possible — or prohibitively expensive.
We build room additions throughout San Jose, Santa Clara, Sunnyvale, Cupertino, Campbell, Los Gatos, Mountain View, Palo Alto, and across the greater Bay Area.
Top-to-bottom transformation. Walls come down, layouts open up, systems get rebuilt. Structural, electrical, plumbing, and finishes — one team, one schedule, one point of accountability.
A whole-home renovation has too many variables to put a number on a webpage and be honest about it. Square footage, the age and condition of the existing structure, how much of the layout is changing, whether the foundation or roof needs work, and how far you’re taking the finishes — each one moves the number substantially. What we will do is give you a line-item proposal before anything starts. You’ll see what every part costs — not an allowance that balloons at month four.
What we handle
Design, structural engineering, Title 24, and city permits — same as every project we take on. Our architect and engineer visit your home before anything is drawn. Structural, electrical, plumbing, HVAC, and finishes are all rebuilt as one coordinated project rather than five separate contractors working around each other.
You’ll see it before we build it
Whole-home projects start with 3D design. Our partner showrooms already have your plan, so material selection is guided rather than overwhelming — cabinets, countertops, tile, flooring, and fixtures, coordinated to the design and delivered on our schedule.
Underestimating the scope of the systems
Homeowners budget for the kitchen and the floors and forget that a house built in 1962 has knob-and-tube wiring, galvanized pipe, and no insulation. The invisible work is often the largest line item.
Phasing it to save money
Doing the kitchen this year and the bathrooms next year sounds prudent, but you pay mobilization twice, you open the same walls twice, and you live in construction twice as long.
Hiring a general contractor after the design is finished
The architect draws something beautiful, the GC prices it, and it comes back well over budget. Now you’re paying to redesign what you already paid to design.
Not planning where to live
A full renovation means moving out. Homeowners who haven’t planned for that end up making rushed, expensive decisions under pressure.
We renovate homes throughout San Jose, Santa Clara, Sunnyvale, Cupertino, Campbell, Los Gatos, Mountain View, Palo Alto, and across the greater Bay Area.
Straight answers about how design-build works, what you’re paying for, and what happens when something goes wrong.
Every project is different, and the best answers come from a real conversation about your home. Book a free consultation or give us a call — we'll walk your space, talk through your goals, and answer every question honestly before you spend a dollar.