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Find Addition to existing structure builders in Sonoma

Avatar for Qualified Builders Construction

Qualified Builders Construction

2206 Oakview Court
5.00(
2
)
Approved Pro

Qualified Builders Construction

2206 Oakview Court
5.00(
2
)
Approved Pro
Customers say: Quick response
Recommended by 100% of Angi customers
Recommended by 100% of HomeAdvisor customers
3 years of experience

Customer satisfaction is what determines our success, which is why we take a hands-on approach. When interacting with Qualified Builders Construction, you'll notice that we're particularly focused on the principles of quality workmanship, timely completion, competitive pricing and integrity in all our business dealings. We combine knowledge and research with our extensive practical experience to ensure a specialized approach for your project needs. Contact us today for a fair and accurate estimate of your project. We look forward to adding you to our long and growing list of happy customers.

"Excellent company! Phenomenal work for the price and I am very happy with the fence they built!"

Mark L on January 2023

Customer satisfaction is what determines our success, which is why we take a hands-on approach. When interacting with Qualified Builders Construction, you'll notice that we're particularly focused on the principles of quality workmanship, timely completion, competitive pricing and integrity in all our business dealings. We combine knowledge and research with our extensive practical experience to ensure a specialized approach for your project needs. Contact us today for a fair and accurate estimate of your project. We look forward to adding you to our long and growing list of happy customers.

"Excellent company! Phenomenal work for the price and I am very happy with the fence they built!"

Mark L on January 2023


Avatar for Grid Design Build

Grid Design Build

1500 3rd St, Suite A
New on HomeAdvisorNew on HomeAdvisor
Approved Pro

Grid Design Build

1500 3rd St, Suite A
New on HomeAdvisorNew on HomeAdvisor
Approved Pro
3 years of experience
Free onsite estimate

We're a locally owned and operated company that values honesty and integrity and treats your home as if it were our own. We offer a variety of General Contractor Home Improvement services that are customizable to each individual project. We specialize in Additions and Kitchen Remodels, but also offer a wide range of expertise for a variety of other projects. We pride ourselves on the quality of our work as well as our commitment to outstanding results. We look forward to building lasting relationships and guarantee your satisfaction!

We're a locally owned and operated company that values honesty and integrity and treats your home as if it were our own. We offer a variety of General Contractor Home Improvement services that are customizable to each individual project. We specialize in Additions and Kitchen Remodels, but also offer a wide range of expertise for a variety of other projects. We pride ourselves on the quality of our work as well as our commitment to outstanding results. We look forward to building lasting relationships and guarantee your satisfaction!


Concept, Design, Develop, Inc.

PO Box 15035
5.00(
4
)
Approved Pro

Concept, Design, Develop, Inc.

PO Box 15035
5.00(
4
)
Approved Pro
Customers say: Quality work
Recommended by 100% of Angi customers
Recommended by 100% of HomeAdvisor customers
10 years of experience

We take great pride in our experience, expertise, quality, and customer service that we provide to meet the consumer's needs. It is our mission to provide excellent workmanship and complete customer satisfaction from start to completion of a project. In order to understand the needs and expectations of our customers, we take great care to work and communicate with every customer in a professional manner. Our reputation is based on service, safety, and quality, regardless of how large or small the job.

"They did an excellent job! We definitely would want to use them again. They just replaced the siding on the sun beaten part of our house. It looks much better than before and matches the rest of the house perfectly. They were responsive and got things done in a timely manner. I recommend vey highly."

Doug W on May 2024

We take great pride in our experience, expertise, quality, and customer service that we provide to meet the consumer's needs. It is our mission to provide excellent workmanship and complete customer satisfaction from start to completion of a project. In order to understand the needs and expectations of our customers, we take great care to work and communicate with every customer in a professional manner. Our reputation is based on service, safety, and quality, regardless of how large or small the job.

"They did an excellent job! We definitely would want to use them again. They just replaced the siding on the sun beaten part of our house. It looks much better than before and matches the rest of the house perfectly. They were responsive and got things done in a timely manner. I recommend vey highly."

Doug W on May 2024


Millstreet Builders

448 Ignacio Blvd, Unit 193
5.00(
2
)
Approved Pro

Millstreet Builders

448 Ignacio Blvd, Unit 193
5.00(
2
)
Approved Pro
Customers say: Quality work
Recommended by 100% of Angi customers
Recommended by 100% of HomeAdvisor customers
5 years of experience

MILLSTREET BUILDERS is dedicated to providing our customers with the best quality and craftsmanship. We are here to build relationships with our customers and communities and to provide our employees with a great place to work. We look forward to working with you!

"Craig was great to work with! Kept on time and on budget"

Stacey R on November 2023

MILLSTREET BUILDERS is dedicated to providing our customers with the best quality and craftsmanship. We are here to build relationships with our customers and communities and to provide our employees with a great place to work. We look forward to working with you!

"Craig was great to work with! Kept on time and on budget"

Stacey R on November 2023


Avatar for Bay Builders, Inc.

Bay Builders, Inc.

936 B 7th St
5.00(
3
)
Approved Pro

Bay Builders, Inc.

936 B 7th St
5.00(
3
)
Approved Pro
Customers say: Quick response
Recommended by 100% of Angi customers
Recommended by 100% of HomeAdvisor customers
24 local quotes requested

We specialize in all phases of remodeling for your home, business, bathrooms, kitchens, finishing basements, and more! We offer a diverse range of services tailored to meet the unique needs of every customer. We take a personalized approach to each project. We work closely with our clients to understand their vision, preferences, and budgetary requirements. We strive to exceed expectations by delivering exceptional service, great quality work, and professionalism on every job. Read more below on all the services we offer and contact us with any questions or to schedule a free estimate today!

"John and his team do amazing work. Built a stunning custom office space with a floor to ceiling library, custom cabinets and custom French doors that blended into our existing home design. I’ve owned a number of homes over the years and I’ve never worked with a builder more dedicated to quality and with more experience than Bay."

Peter and Nancy T on February 2025

We specialize in all phases of remodeling for your home, business, bathrooms, kitchens, finishing basements, and more! We offer a diverse range of services tailored to meet the unique needs of every customer. We take a personalized approach to each project. We work closely with our clients to understand their vision, preferences, and budgetary requirements. We strive to exceed expectations by delivering exceptional service, great quality work, and professionalism on every job. Read more below on all the services we offer and contact us with any questions or to schedule a free estimate today!

"John and his team do amazing work. Built a stunning custom office space with a floor to ceiling library, custom cabinets and custom French doors that blended into our existing home design. I’ve owned a number of homes over the years and I’ve never worked with a builder more dedicated to quality and with more experience than Bay."

Peter and Nancy T on February 2025


Avatar for Coastal View Builder

Coastal View Builder

200 South Main Street Box 216
4.67(
12
)
Approved Pro

Coastal View Builder

200 South Main Street Box 216
4.67(
12
)
Approved Pro
Super Service Award
Customers say: Quick response
32 local quotes requested
6 years of experience

Look no further. Here at Coastal View Builder we specialize in Residential and Commercial Remodeling. additions, decks, doors, windows, and so much more! We offer a diverse range of services tailored to meet the unique needs of every customer. We take a personalized approach to each project. We work closely with our clients to understand their vision, preferences, and budgetary requirements. We strive to exceed expectations by delivering exceptional service, great quality work, and professionalism on every job. Read more below on all the services we offer and contact us with any questions or to schedule a free estimate today!

"We are very happy with the results and would like to give 4.5 stars if we could. They're a great company to work with and the job was fairly priced and done well. We would definitely work with CVB again. In addition to the kitchen remodel, they also did work on another house project and we were thoroughly satisfied. Our only suggestion is for the crew to be better prepared when getting to the job site. Additional time was spent collecting/buying tools and material after arriving."

Dana F on October 2025

Look no further. Here at Coastal View Builder we specialize in Residential and Commercial Remodeling. additions, decks, doors, windows, and so much more! We offer a diverse range of services tailored to meet the unique needs of every customer. We take a personalized approach to each project. We work closely with our clients to understand their vision, preferences, and budgetary requirements. We strive to exceed expectations by delivering exceptional service, great quality work, and professionalism on every job. Read more below on all the services we offer and contact us with any questions or to schedule a free estimate today!

"We are very happy with the results and would like to give 4.5 stars if we could. They're a great company to work with and the job was fairly priced and done well. We would definitely work with CVB again. In addition to the kitchen remodel, they also did work on another house project and we were thoroughly satisfied. Our only suggestion is for the crew to be better prepared when getting to the job site. Additional time was spent collecting/buying tools and material after arriving."

Dana F on October 2025


Homes West Construction

P.O. Box 2453
2.75(
3
)
Approved Pro

Homes West Construction

P.O. Box 2453
2.75(
3
)
Approved Pro
23 years of experience
Free onsite estimate

Homes West Construction provides top quality work in the Napa area specializing in structural repairs, remodels and new construction. Our professional crew is proficient in all areas of the building process and are dedicated to delivering an excellent product at a competitive price and in a timely fashion.

"Great contractor. He helped to design and pick out fixtures. Excellent work doing my front porch in three weeks."

Robert P on December 2020

Homes West Construction provides top quality work in the Napa area specializing in structural repairs, remodels and new construction. Our professional crew is proficient in all areas of the building process and are dedicated to delivering an excellent product at a competitive price and in a timely fashion.

"Great contractor. He helped to design and pick out fixtures. Excellent work doing my front porch in three weeks."

Robert P on December 2020


Avatar for Morgan C Winslow A Partnership

Morgan C Winslow A Partnership

8901 Jeannette Avenue
New on HomeAdvisorNew on HomeAdvisor
Approved Pro

Morgan C Winslow A Partnership

8901 Jeannette Avenue
New on HomeAdvisorNew on HomeAdvisor
Approved Pro
31 years of experience
Free onsite estimate

Morgan C Winslow A Partnership is dedicated to providing our customers with the best quality and craftsmanship. We are here to build relationships with our customers and communities and to provide our employees with a great place to work. We look forward to working with you!!!!!

Morgan C Winslow A Partnership is dedicated to providing our customers with the best quality and craftsmanship. We are here to build relationships with our customers and communities and to provide our employees with a great place to work. We look forward to working with you!!!!!


Avatar for Taragano Design and Build

Taragano Design and Build

4494 Snow Berry Court
5.00(
1
)
Approved Pro

Taragano Design and Build

4494 Snow Berry Court
5.00(
1
)
Approved Pro
13 local quotes requested
Free onsite estimate

We pride our company on reliability, great communication, integrity, and quality work. We are experts in our trade and will do our best to keep you as educated as we can on your particular task or project. We look forward to earning your business!

"Working with yaniv has been fantastic front to back. He is on top of every detail and has exceed our expectations in regards to quality and timeline. He has guided us in the right direction with every step. Whether it was small things like how to set up electrical or broader topics like the design of our bathroom he has been so knowledgeable and clearly customized his approach to what he knows we want and need. We absolutely work with him again. "

Ben L on July 2025

We pride our company on reliability, great communication, integrity, and quality work. We are experts in our trade and will do our best to keep you as educated as we can on your particular task or project. We look forward to earning your business!

"Working with yaniv has been fantastic front to back. He is on top of every detail and has exceed our expectations in regards to quality and timeline. He has guided us in the right direction with every step. Whether it was small things like how to set up electrical or broader topics like the design of our bathroom he has been so knowledgeable and clearly customized his approach to what he knows we want and need. We absolutely work with him again. "

Ben L on July 2025


Community First Construction Corp.

1700 Peggy Ct
New on HomeAdvisorNew on HomeAdvisor
Approved Pro

Community First Construction Corp.

1700 Peggy Ct
New on HomeAdvisorNew on HomeAdvisor
Approved Pro
18 years of experience
Free onsite estimate

Community First Construction Corp. is committed to excellence in every aspect of our business. We uphold a standard of integrity bound by fairness, honesty and personal responsibility. Our distinction is the quality of service we bring to our customers. Accurate knowledge of our trade combined with ability is what makes us true professionals. Above all, we are watchful of our customers' interests, and make their concerns the basis of our business.

Community First Construction Corp. is committed to excellence in every aspect of our business. We uphold a standard of integrity bound by fairness, honesty and personal responsibility. Our distinction is the quality of service we bring to our customers. Accurate knowledge of our trade combined with ability is what makes us true professionals. Above all, we are watchful of our customers' interests, and make their concerns the basis of our business.

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FAQs for addition to existing structure building service projects in Sonoma, CA

Yes, hidden rooms are legal, as long as they meet all local building regulations. If you sell your house, most states require homeowners to disclose full houseplans, which would include any hidden rooms.

If your secret room is a safe room, it should contain a means of communication aside from a cell phone, such as a shortwave radio. You should also have plenty of drinking water, a portable generator, emergency food supplies, blankets, pillows, flashlights, batteries and a first aid kit.

Any time you update your home’s square footage, you increase its value, but a secret room is a niche feature that doesn't rank high on every buyer’s list of must-haves. Investing your money in remodeling more common living areas like bedrooms, bathrooms, or kitchens will have a higher ROI than adding a secret room. Many secret rooms can act as entertainment spaces (think a game room or wine cellar) or quiet spaces (a library or study), so when building your secret room you may want to consider its versatility for when you’re ready to sell.

The Sonoma, CA homeowners’ guide to addition to existing structure building services

From average costs to expert advice, get all the answers you need to get your job done.

  • A renovated kitchen with a waterfall island

    HomeAdvisor’s DIY Kitchen Remodel Cost Guide looks at the cost of buying supplies and doing the work yourself. Find the key cost factors and how to cut expenses.

  • Secret room within bookcase

    HomeAdvisor's expert guide walks you through the cost to build a secret room, whether you're creating a safe room for security or a fun space to fulfil your childhood fantasies. Use this guide to help plan your secret room project and explore room, concea

  • outdoor patio bar

    Explore the cost to build a bar in your home and learn how materials, wet vs. dry bars, and labor costs influence the total price of your project.