Home Additions
Moving is expensive. Building the space you actually need is smarter. We build home additions in Los Gatos, Saratoga, Cupertino, Sunnyvale, Los Altos, and throughout the Bay Area.
- 10+ years of remodeling experience
- 5-year workmanship warranty
- Full-service, concept to final walkthrough
- Clean jobsite, every day
Scroll down to discover what we build, our process, and what to expect.
A Home Addition Built the Way It Should Be
When your home no longer fits your needs, adding more living square footage makes perfect sense.
Whether you need an extra bedroom, a beautiful sunroom addition, a garage extension, or an entire second story addition for a growing family…
That’s where we come in.
We’ll take care of the design, planning, permitting, inspection, and the smooth coordination of every tradesmen and worker in your home.
You’ll know where the project stands, what’s coming next, and what things cost before they happen.
A home addition done right adds a ton of value and living square footage to your home and lifestyle.
What we work on:
- Room additions and expansions
- Garage conversions
- Sunrooms & porches
- Second-story additions
- Master suite additions
- Basement additions
- In-law suites and guest quarters
- Detached structure additions
- Home bump-outs
Check Out These Amazing Home Additions
The Questions Worth Asking Before You Start
Somewhere between two and three and a half months for most projects, though that depends heavily on what’s involved.
A garage conversion is a different animal than a full structural addition that requires raising a foundation and rerouting plumbing.
We give you a timeline based on your actual project before any work starts, and we typically finish ahead of it.
The scope surprises a lot of homeowners. Foundation, framing, electrical, plumbing, siding, roofing, permits, inspections, drywall, tile, flooring. It’s not one trade, it’s many, and they all have to move in the right sequence.
We lay all of that out for you upfront so you know exactly what you’re getting into before you commit.
Yes, that’s part of the job. We coordinate permits and inspections from start to finish. You don’t have to manage that process on your own.
We can help coordinate plans and layouts as part of the project. We’ll walk you through what’s needed at the initial consultation.
Every addition we build carries manufacturer warranties on installed products, plus our 5-year workmanship warranty on the labor.
If something we built isn’t holding up the way it should, we come back and fix it.
The warranty covers workmanship and installation. It doesn’t cover damage from misuse or normal wear, but for everything we put our hands on, we stand behind it.
That depends on your lot size, local zoning rules, and what the existing structure can support. We assess all of that during the initial walkthrough and walk you through what’s realistically buildable on your property before anything gets drawn up.
Yes, and that’s something we pay close attention to. The materials, the roofline, the way the new space connects to the old one.
A good addition shouldn’t look like it was built separately and attached later. We think through how everything ties together before the first wall goes up.
Case Studies For Home Additions In California
300 sq. ft. Detached ADU or JADU
- Design, planning, and construction
- Kitchenette with semi-custom cabinets
- Small bathroom with tub/shower combo
- Luxury Vinyl flooring
- Electrical, plumbing, and HVAC installation
- Small wood covered porch
- Asphalt shingles
- LP, Vinyl, or cement board siding
- ProVia, Andersen, or Marvin windows
The price for an addition like this would start at $150,000.
Covered Deck Addition
- Design, planning, and construction
- Roof extension with matching shingles
- Energy-efficient windows or screening system
- Accent cedar ceiling with lighting
- Composite decking for low-maintenance
- Engineered wood for siding and trim
- #1 PT Lumber for the deck framing
A deck addition like this starts from $60,000.
Home Bump-Out Addition
- Bump-out addition extending exterior wall to enlarge living area
- Installation of multiple large windows for natural light and backyard views
- Vaulted ceiling concept to create a more open and airy feel
- Flooring extension to seamlessly match existing interior
- Structural framing and roofline tie-in to integrate with existing home
- Interior finishing including drywall, paint, and trim work
- Updated lighting fixture and electrical adjustments
An 180 sq. ft. bump-out addition starts at $120,000.
Why Homeowners in the Bay Area Choose MA Legacy
These are the standards that shape every addition we build.
10 Years of Experience Behind Every Addition
Home additions are among the most complex residential projects a contractor can take on. Having done them well before means we know where things can go wrong and we make sure they don’t.
A 5-Year Warranty on Our Work
Manufacturer warranties on every product we install, plus five years on our labor. If something we built isn’t right, we come back and make it right. We back the work because we’re confident in how it’s done.
Real-Time Updates Through CompanyCam
An addition is a long project with a lot of moving parts. We use CompanyCam throughout to send you photo updates as each phase progresses, so you always know what’s happening without needing to be on site every day.
The Kind of Detail Work Most Contractors Skip
The finish on the trim. The consistency of the tile. The way the new space connects to the existing home. Our benchmark is the same: if we wouldn’t accept it in our own home, it doesn’t go in yours. That standard applies to every phase of the addition, not just what’s visible.
One Team Managing the Whole Project
No sorting through separate subcontractors or tracking down different tradespeople yourself. We coordinate every trade involved so the work moves in the right sequence, nothing gets missed, and you have one person to call with questions.
A Process That Keeps You in the Loop
We keep your home organized, protected, and treated with care throughout every phase of the build.
1. Collaborate
We walk the property, talk through what you want to build and why, and nail down the scope, design direction, permits needed, and a realistic timeline before anything gets touched.
2. Build
We manage every phase from foundation and framing through electrical, plumbing, drywall, and all finish work. The site stays contained and clean, and you get regular photo updates throughout.
3. Enjoy
You get a finished addition that functions the way you always wanted it to, built to a standard you’ll still appreciate years from now.
Here Is What You Get When You Work With Us
Built on consistent workmanship and partnerships with trusted manufacturers in the industry.
A Clear Scope Before Anything Starts
We tell you exactly what the project involves, what it costs, and how long it takes before you sign anything. If anything changes during the build, you’re informed immediately.
An Addition That Fits the Home It's Attached To
The new space should feel like it belongs, not like it was tacked on. We think through how the addition connects to the existing structure in layout, finish, and flow.
Work Finished to a Standard That Lasts
Clean lines, quality materials, details that were thought through before the first nail went in. A home addition is a long-term investment.
You've Outgrown the Space. We Can Help You Do Something About It.
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