CREATE MORE SPACE WITHOUT LEAVING THE HOME YOU LOVE.

HOME ADDITIONS IN SAN JOSE & THE BAY AREA

Whether your expanding your kitchen, adding a new bedroom, building a larger primary suite, or creating a second-story addition, Diamond Group Builders helps Bay Area homeowners create beautiful, functional living spaces tailored to their needs.

From planning and permits to construction and final finishes, we manage the entire process with quality craftsmanship, clear communication, and a commitment to lasting value.

HOME ADDITIONS SAN JOSE | DIAMOND GROUP BUILDERS, INC.

Adding a room addition or a second-story addition is one of the most effective ways to gain extra living space while increasing property value. Diamond Group Builders works with San Jose homeowners to create thoughtful additions that complement your existing home and match your lifestyle. Our team provides expert guidance, clear timelines, and a stress-free process so you can enjoy your new spaces with great pride.

Our design team develops plans that balance function, style, and long-term value. We guide you through permitting, construction, and finishing, delivering a finished project that fits your goals and budget.

OUR SERVICES

Diamond Group Builders offers a wide range of home improvement projects in San Jose. We handle project sizes of all scales and deliver quality work backed by licensed professionals.

Room Additions

Expand your living space with a new bedroom, family room, or in-law unit. Each room addition blends seamlessly with your home and creates extra space your family will love.

Second Story Additions

Add square footage and extra living areas above your home for growing families or those seeking more space without altering the footprint of your property.

Kitchen Remodeling

Our full kitchen remodeling services update layouts, materials, and finishes to create functional and stylish kitchens that fit your lifestyle.

Bathroom Additions

We design and construct bathrooms that complement your home while increasing home value and long-term usability.

ADU & In-Law Units

We combine ADU construction with home additions to provide flexible living space, private suites for family, or rental income opportunities.

Permitting & Project Management

Our project managers and licensed professionals handle the entire permitting process and coordinate the construction process to keep your project on track with clear timelines.

A CLEAR PATH TO YOUR DREAM HOME ADDITION

At Diamond Group Builders, Inc., we stand out as a top-rated contractor and designer in San Jose 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.

WHAT MAKES OUR HOME ADDITIONS EXCEPTIONAL

Blending Seamlessly with Your Home

A well-crafted home addition blends naturally with your existing home. Each room addition, family room, or new bedroom is designed to enhance your home’s architecture and improve the functionality of your living spaces.

Built for the Future

Our additions are built to adapt as your lifestyle changes. Perhaps you’re planning to grow your family, add in-law units, or create a flexible living area. No matter what, your new spaces will remain useful and relevant for years to come.

Designed Around You

Every home improvement project reflects how you live. From extra bedrooms and cozy family rooms to functional workspaces and guest suites, we design each addition to fit your unique needs while adding value and comfort.

Style That Complements Your Home

Your home addition should feel like it belongs. We select materials, finishes, and layouts that match or enhance your home’s existing style, creating spaces that look intentional and polished.

See Our Work in Action

ADU Build

Home Remodeling

Kitchen Remodeling

FEATURED PROJECTS

Over the years, we’ve completed a variety of home additions in San Jose, ranging from second-story expansions to full kitchen remodeling and new bedrooms. Each project is customized to match the home’s architecture while providing more space, energy efficiency, and functional living areas for families.

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

WHAT OUR CLIENTS SAY

Our clients praise our outstanding customer service, quality work, and ability to deliver projects on time and within budget. Homeowners appreciate our hands-on approach, expert guidance, and commitment to creating spaces that enhance life and lifestyle.

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

Q. What types of home additions can Diamond Group Builders build?

We construct room additions, second-story additions, new bedrooms, family rooms, kitchens, bathrooms, and in-law units, all designed to match your home and lifestyle.

Q. How long does a home addition project take?

Timelines vary depending on project size and complexity. After reviewing your goals, we provide clear timelines and detailed estimates for the full scope of work.

Q. Can I expand my home while maintaining energy efficiency?

Yes. We select materials and designs that improve energy efficiency while adding square footage and functionality.

Q. Do you handle permits and local building codes?

Yes. Our fully licensed team guides homeowners through the entire permitting process and complies with all local building codes.

Q. Can home additions generate rental income?

Absolutely. Adding an in-law unit or accessory dwelling can provide extra living space for family or tenants, boosting home value and long-term financial benefits.

Q. How do I know my home addition will match my existing home?

Our design team evaluates your home’s architecture and develops thoughtful plans that integrate seamlessly with your property.

START YOUR HOME ADDITION TODAY — GET IN TOUCH BELOW.

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