GS Design and Build · Campbell, CA

Top Rated ADU Builders & Design-Build Firm in the Bay Area

From custom ADUs and full home remodels to kitchen transformations and architectural additions — GS Design and Build brings 15 years of award-winning craftsmanship to Silicon Valley homeowners who demand the best.

(415) 933-2547
4.9 52+ Google reviews

Certified

Insured

Reliable

Honorable

Experienced

General Contractor services in

From emergency tarping to full reroofs and wind mitigation reports, we help you choose the right roof work without pressure or guesswork.

Not sure whether you need repairs, remodeling, renovations, or a full rebuild? We'll assess your project at no cost.

Call (415) 933-2547
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.

Our Full Story

A Process Built Around You

We believe great construction starts with great communication. Our streamlined process keeps you informed and in control from the first conversation to the final walkthrough.

Consultation

Tell us about your project — ADU, remodel, or addition. We listen to your goals and answer questions about scope and next steps.

Design & Planning

Our team develops detailed architectural plans tailored to your vision, budget, and site — setting the foundation for a smooth build.

Permits & Approvals

We handle all permit applications and coordinate with city and county agencies to secure approvals and keep your project on schedule.

Construction

Our crew executes the work with precision and care. You receive regular updates while we manage quality checks and site cleanliness.

Final Walkthrough

We walk through the finished project with you, address any last adjustments, and hand over your completed space with confidence.

We handle all permits, inspections, and cleanup. You approve each phase before we move forward.

General Contractor Services Across
CA Service Area

Based in Campbell — serving every corner of CA Service Area.

Primary Service Area

Los Gatos, CA

Los Gatos sits in the Santa Cruz Mountains foothills with tree-lined streets and established residential neighborhoods. The area spans from downtown's walkable core to hillside properties with varied lot sizes and architectural styles. Local homes often feature mature landscaping and custom updates.

Cities & Communities We Serve:

Los GatosSaratogaMonte SerenoCampbell
Los Gatos, CA Services

What Santa Clara County homeowners say.

4.9
52 Google reviews

Worked with us?

Leave a Review

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

Ready to become our next happy client?

(415) 933-2547

Common Questions About General Contractor in Los Gatos, CA

Answers to the questions homeowners ask most before hiring a contractor. Not seeing yours? Call us. We are straightforward about our process, pricing, and expectations.

We primarily serve Los Gatos, CA, Palo Alto, CA, San Mateo, CA, San Jose, CA, Fremont, CA, Redwood City, CA, Sunnyvale, CA, Menlo Park, CA, Hillsborough, San Carlos, Burlingame, Foster City. If you are outside these areas, call us. We take select projects beyond our standard service radius for the right scope.

Most ADU projects take 4-6 months from permit approval to completion, depending on size and complexity.

Yes. We manage all Campbell city permits, inspections, and code compliance throughout the project.

Costs vary by size and finishes, typically $150K-$300K. We provide detailed estimates after site evaluation.

Still have questions?

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Call (415) 933-2547

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

Ready to Build Something Exceptional?

GS Design and Build serves Los Gatos, CA and the surrounding area with professional General Contractor services. Free estimates, clear options, no pressure.

15+ Years Residential Construction Experience
Family-Owned and Operated
ADU Specialists
Full Remodel Services
Multi-City Service Coverage
Call (415) 933-2547

Mon–Fri 8:00 AM - 7:00 PM · Sat Closed · Responses within 2 hrs