General Contractor backed by 17+ years of local experience

We are a family-owned construction firm with 15 years of experience building and remodeling homes across Silicon Valley. Every project we take on reflects our commitment to quality, transparency, and lasting results.

17+

Years Serving

12

Service Areas

15+

Services Offered

Construction crew and tools on a residential job site, showcasing professional building and remodeling equipment.

17+

Years Serving
Santa Clara County

Built on Craftsmanship.
Driven by Trust.

GS Design and Build is a family-owned construction company based in Campbell, CA. We serve homeowners across the South Bay and Peninsula with residential construction work that is built to last. From ADUs and full home remodels to kitchen and bathroom renovations, we handle projects of all sizes with care and precision.

Our founder, Gershon (Geri), has spent 15 years working in residential construction across the Bay Area. He started GS Design and Build because he saw a gap in the market: homeowners needed a contractor they could actually trust, one who showed up, communicated clearly, and delivered work they were proud of. That mission still drives every project we take on.

We specialize in accessory dwelling units (ADUs), home additions, full remodels, kitchen and bathroom renovations, interior and exterior remodeling, hardscape, foundation work, and window installation. Whether you are adding a rental unit to your property or updating a kitchen that has not been touched in 20 years, we bring the same level of attention to every job.

Our work takes us throughout the South Bay and Peninsula, including Los Gatos, Los Altos, Palo Alto, Menlo Park, Mountain View, Atherton, San Mateo, San Carlos, Burlingame, Sunnyvale, Santa Clara, Saratoga, San Jose, Redwood City, Millbrae, Foster City, Milpitas, and Fremont. We know these neighborhoods well, and we understand what homeowners here expect from a contractor.

What sets us apart is simple: we treat your home the way we would treat our own. As a family business, our reputation is tied directly to the quality of our work. We do not cut corners, and we do not disappear after the contract is signed. Geri and his team stay involved from the first walkthrough to the final inspection.

Over 15 years, Geri has built a long list of satisfied customers who come back to us for their next project and refer us to their neighbors. That track record is something we take seriously. It keeps us honest, and it keeps our standards high.

If you are planning an ADU, a remodel, or any residential construction project in the Bay Area, we would love to hear about it. Call us today at (415) 933-2547 or email gsdesignandbuild1@gmail.com to request your free estimate. We are available Monday through Friday, 8am to 7pm.

Why Homeowners Choose GS Design and Build

15 Years of Experience

Gershon (Geri) has spent 15 years working in residential construction across the South Bay and Peninsula. That hands-on background shapes every project we take on.

ADU Specialists

We build accessory dwelling units from the ground up, handling design, permits, and construction under one roof. You get a finished unit without juggling multiple contractors.

Licensed and Insured

We carry the proper licensing and insurance required for residential construction in California. You are protected at every stage of your project.

Family-Owned Accountability

As a family-owned business, our name is on every job we complete. We stay involved from the first walkthrough to the final inspection.

Clear Communication

We keep you informed at each phase so there are no surprises. You always know what is happening on your property and what comes next.

Full-Scope Services

From kitchen and bathroom remodels to additions, hardscape, windows, and foundations, we handle the full range of residential work. One team, one point of contact.

What Santa Clara County homeowners say.

4.9
52 Google reviews

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From our very first appointment with Gershon, we felt confident we were in excellent hands. He listened carefully to what we wanted, offered thoughtful design suggestions, and walked us through the process and timeline in a clear, transparent way. Every step—from initial design and planning to the finishing touches—was handled smoothly, with consistent updates so we always knew what was happening next. The crew that worked on our home was hard working, professional, and very knowledgeable. They arrived on time, respected our home, and kept the work area as tidy as possible, which we really appreciated. The finished kitchen looks fantastic and functions even better than we hoped and the quality of the workmanship really stands out. Friends and family have already commented on how beautiful and well thought-out the space is. We would not hesitate to hire GS Design & Build again for future projects. If you’re looking for a top-tier contractor for your home remodeling, GS Design & Build are an outstanding choice.

Charles Decker, DC, ACN Google review · June 2026

GS Design and build did an amazing job uplifting my garage. Gheri was the most responsive of the contractors I got quotes from and he was very quick to respond with a reasonable estimate. He was always reachable and ensured the team was very punctual. His crew did a great job completing the job and handling surprises. I didn’t have to contact Gheri for anything during the job. The final work quality was great and my garage looks great! I will highly recommend GS Design and Build for your home improvements Update: i did a bathroom remodel with them 6 months after the garage upgrade and it was amazing! The team has remained consistent with their quality and workmanship!

viswanathan vaidyanathan Google review · June 2026

We used GS Design and Build for a room addition in Redwood City and couldn’t be happier. Geri helped us figure out the best layout for our new sunroom and made sure the style blended with the rest of our house. Her crew worked clean and fast, and everything passed inspection the first time. The project wrapped up on schedule and within our budget. The space gets amazing light and has quickly become our favorite part of the house. If you’re in the market for a room addition contractor who truly listens and executes, don’t look any further.

Ronda Richardson Google review · September 2025

Just got my home addition done! GS design helped us build a new bathroom and a new master bed in new construction. Everything was fully licensed and Geri managed everything at his end. I found Geri on Nextdoor and was nervous before signing him up but to my surprise, I couldn’t have asked for more! He has a lovely team of people who specialize in what they do. Geri cared for me and made sure I am satisfied at each step. He gave me a good run down of what he plans to do in the coming week which was very satisfying. Geri’s rates were also very competitive and he was reasonable when the work order changed. What I liked about Geri a lot is also that his interior designing skills are also very strong so he guided us when the size of the window was off or in making lovely choices of the flooring. You can trust Geri blindly and go with him. You will not regret it. Thanks Geri, for all the great work.

Vedant Dhandhania Google review · April 2022

We live in Redwood City and reached out to GS Design and Build for a second-story room addition. Geri coordinated with our structural engineer and managed the project with confidence. We were impressed with how smoothly everything went. Her communication throughout the process was excellent. The new space has completely transformed our home and given us the extra flexibility we needed. Top-notch room addition contractor and a pleasure to work with.

Deanna Callison Google review · September 2025

Proudly Based in Campbell, CA

Stop by, call, or book online — we're always nearby when you need us.

Hours

  • Monday 8:00 AM - 7:00 PM
  • Tuesday 8:00 AM - 7:00 PM
  • Wednesday 8:00 AM - 7:00 PM
  • Thursday 8:00 AM - 7:00 PM
  • Friday 8:00 AM - 7:00 PM
  • Saturday Closed
  • Sunday Closed
Free, No-Obligation Estimate

Ready to start your project with a team you can trust?

Call (415) 933-2547 or send us an email to request your free estimate. We are available Monday through Friday, 8am to 7pm, and we serve homeowners across the South Bay and Peninsula.

Call (415) 933-2547
15+ Years Residential Construction Experience Family-Owned and Operated ADU Specialists