ADU Builders Portola Valley

Unlock the Potential of Your Portola Valley Property with a Perfect ADU

Adding an ADU (Accessory Dwelling Unit) is one of the smartest ways to expand your living space and transform your Portola Valley home. It can help create extra space for your family or even generate rental income, with a well-designed ADU that is able to enhance your main house and fit your lifestyle. As experienced ADU builders in Portola Valley, Diamond Group Builders specializes in complete ADU construction services from blueprints to finishing touches.

Featured Projects

We’ve completed over 40 large-scale residential projects in Portola Valley, including attached ADUs, detached units, and garage conversions. Each project is tailored to the homeowner’s goals and style, delivering functional and beautiful living areas that add value and lifestyle benefits.

Inside This Beautiful Custom ADU in Willow Glen

Diamond Group Builders completed this custom detached ADU in San Jose, adding 997 square feet of functional living space. This

Luxury Custom ADU in Santa Clara With Warm Modern Design

Diamond Group Builders completed this custom ADU in Santa Clara to create a modern backyard living space. The project replaced

A Stunning Menlo Park Full Home Remodel & Addition

Diamond Group Builders completed this custom Menlo Park home remodel and addition to completely transform the original 1940s home. The

A Stunning Luxury Modern Ranch Custom Home

This modern ranch custom home combines comfort, function, and high-end craftsmanship. The 2,968 sq. ft. single-story layout includes 4 bedrooms,

Timeless Elegance: San Jose, CA Bathroom Transformation

Elevate your San Jose home with the expertise of Diamond Group Builders, your premier choice for home remodeling. As the

Modern Luxury Bathroom Remodel in Santa Clara

Diamond Group Builders completed this custom luxury bathroom remodel in Santa Clara with a bold and modern design. The space features a

Our Services

Diamond Group Builders offers a full range of ADU construction services, guiding homeowners through every step of the project.

Attached ADUs

Expand your home with a unit connected to your main house, creating seamless access and additional living space for family or guests.

Detached ADUs

Freestanding ADUs provide privacy and flexibility, ideal for rentals, home offices, or multigenerational living

Garage Conversions

Transform underused garages into functional ADUs with bathroom, kitchen, and living areas, maximizing your property’s potential.

Custom Designs & Blueprints

We create tailored plans and layouts to match your style, lifestyle, and property constraints, ensuring a perfect ADU.

Remodeling & Finishing Touches

We oversee every detail of your ADU, including walls, electrical, kitchen, and bathroom installations, to deliver high-quality workmanship.

Financing & Pricing Assistance

Our team helps homeowners explore loans, credit, and financing options so your project stays on budget without sacrificing quality.

Our Process

At Diamond Group Builders, Inc., we stand out as a top-rated contractor and designer in Portola Valley and the surrounding areas. Here’s why you should choose us for your next project:

Step One: Consultation & Vision Planning

As a licensed and experienced contractor, we have the expertise to handle all aspects of your home building or remodeling project. From obtaining permits to managing subcontractors, we ensure a smooth and efficient construction process.

Step Two: Custom Design & Proposal

Our design team develops tailored layouts and detailed plans. We refine every element until your home addition perfectly aligns with your vision, your home’s architecture, and desired square footage.

Step Three: Material Selection & Planning

Select flooring, finishes, and materials with guidance from our experts. Every choice is designed to add quality, style, and functionality to your new rooms, family areas, or in-law units.

Step Four: Construction & Installation

Our experienced team and project managers handle all construction tasks. From structural changes to kitchen and bathroom remodeling, we manage every aspect to deliver a finished project that meets your expectations.

Step Five: Final Walk & Handover

Once construction is complete, we'll walk through your new spaces together. This is your opportunity to review every detail, confirm your satisfaction, and enjoy your expanded home ready for daily life and lifestyle improvements.

Reviews

Our clients praise us for customer satisfaction, clear communication, and hands-on involvement. Homeowners love our attention to detail, professionalism, and ability to transform properties into functional, stylish spaces. Read our reviews to see why we’re one of Portola Valley’s most trusted ADU contractors.

Josh Yee

We worked with John and his team as a part of a bathroom remodel project. They were really easy to work with, and were extremely responsive. The […]

Laura Guntren

I had a broken pipe and cracked shower pan do some flood damage to a bathroom, so ended up needing to rebuild the shower. John and his team […]

Chris Conner

John and Deanna were both very easy to work with. John fixed every issue that would come up and made sure we were happy. Deanna gave many […]

Matt Wong

Diamond Group Builders, Inc. was a referral from a friend that had previously used them for a bathroom remodel. We had gotten a couple of quotes […]

Pete Rivera

Johnny and his team did excellent job painting our house and helping install new doors. Johnny and his team are extremely professional and really go […]

Felix Adler

John and his team did a fantastic job with our bathroom remodel this year. Courteous, professional, prompt, and easy to communicate with. They […]

Frequently Asked Questions About ADUs

Q. What types of ADUs can you build in Portola Valley?

Attached ADUs, detached units, garage conversions, and home additions, each designed to fit your property and expand living space.

Q. How long does construction take?

Project timelines vary. After reviewing your plans, we provide a detailed schedule covering construction and finishing touches.

Q. Can you assist with financing?

Yes. We guide homeowners through loans, credit, and financing options to make the project manageable.

Q. Do ADUs increase property value?

A well-designed ADU adds extra space, rental potential, and enhances the overall lifestyle and appeal of your property.

Q. Are permits required for ADUs in Portola Valley?

Yes. As a licensed general contractor, we navigate all city requirements and zoning rules to keep your project compliant.

Q. Can a garage conversion become a full ADU?

Absolutely. We convert garages into complete living areas with bathroom, kitchen, and bedrooms, tailored to your needs.

Q. How do I choose the right ADU design?

We assess your property, goals, and lifestyle, then provide customized plans and blueprints to create a perfect ADU.

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