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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 Angi
Approved Pro
Grid Design Build
1500 3rd St, Suite A
New on AngiNew 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!


Homes West Construction
P.O. Box 2453
2.75(
3
)
Approved Pro
Homes West Construction
P.O. Box 2453
2.75(
3
)
Approved Pro
10 local quotes requested
23 years of experience

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


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


Wadleigh Group, Inc.
214 Club Drive
New on HomeAdvisorNew on Angi
Approved Pro
Wadleigh Group, Inc.
214 Club Drive
New on AngiNew on HomeAdvisor
Approved Pro
12 local quotes requested
18 years of experience

Wadleigh Group, 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.

Wadleigh Group, 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.


Avatar for BE HOME REMODELING INC
BE HOME REMODELING INC
282 Bayview Ave
4.94(
9
)
Approved Pro
BE HOME REMODELING INC
282 Bayview Ave
4.94(
9
)
Approved Pro
Customers say: Quick response
59 local quotes requested
1 years of experience

Be Home Remodeling is a home improvement company dedicated to transforming spaces with quality craftsmanship and personalized service. We specialize in a range of remodeling projects, from kitchens and bathrooms to full home renovations, back yard remodeling and more. Our team of experienced professionals collaborates closely with clients to understand their vision and bring it to life, ensuring each project reflects their style and meets their needs. Whether you're looking to update a single room or undertake a complete overhaul, Be Home Remodeling is here to make your dream home a reality.

"The good job was done on time. Highly recommend.."

George W on June 2025

Be Home Remodeling is a home improvement company dedicated to transforming spaces with quality craftsmanship and personalized service. We specialize in a range of remodeling projects, from kitchens and bathrooms to full home renovations, back yard remodeling and more. Our team of experienced professionals collaborates closely with clients to understand their vision and bring it to life, ensuring each project reflects their style and meets their needs. Whether you're looking to update a single room or undertake a complete overhaul, Be Home Remodeling is here to make your dream home a reality.

"The good job was done on time. Highly recommend.."

George W on June 2025


R deLeon Construction
7 Bret Harte Rd
New on HomeAdvisorNew on Angi
Approved Pro
R deLeon Construction
7 Bret Harte Rd
New on AngiNew on HomeAdvisor
Approved Pro
36 local quotes requested
3 years of experience

R deLeon Construction 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.

R deLeon Construction 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.


Avatar for Prosper Construction Development, Inc.
Prosper Construction Development, Inc.
180 Steuart St., Box 194631
4.88(
38
)
Approved Pro
Prosper Construction Development, Inc.
180 Steuart St., Box 194631
4.88(
38
)
Approved Pro
Customers say: Quick response
Recommended by 97% of Angi customers
Recommended by 97% of HomeAdvisor customers
231 local quotes requested

We are 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 services that are customizable to each individual project. You will find us to be competitively priced, paying close attention to the details of each and every project that we are involved with. We look forward to building lasting relationships, and guarantee your satisfaction!

"Fast response and clear communication throughout the process."

Marco T on April 2025

We are 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 services that are customizable to each individual project. You will find us to be competitively priced, paying close attention to the details of each and every project that we are involved with. We look forward to building lasting relationships, and guarantee your satisfaction!

"Fast response and clear communication throughout the process."

Marco T on April 2025


RSF Construction Inc.
6910 Monte Verde Drive
New on HomeAdvisorNew on Angi
Approved Pro
RSF Construction Inc.
6910 Monte Verde Drive
New on AngiNew on HomeAdvisor
Approved Pro
223 local quotes requested
6 years of experience

RSF Construction Inc. is a leader in providing our customers with the highest quality service in an honest, efficient, and professional way. Our pledge is to create successful relationships with our customers, employees and community by building trust, treating every project with the utmost integrity and exceeding expectations. We look forward to working with you!

RSF Construction Inc. is a leader in providing our customers with the highest quality service in an honest, efficient, and professional way. Our pledge is to create successful relationships with our customers, employees and community by building trust, treating every project with the utmost integrity and exceeding expectations. We look forward to working with you!

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

Building an in-law suite takes between two and seven months. Converting an existing basement, attic, or room can be done in about two months. Constructing a new addition or detached suite often takes four to five months for construction, plus one to two months for permits. The bigger the suite, the longer it will take. 

Yes, you can build an in-law suite in your backyard if you meet local building codes and zoning regulations. An in-law suite often occupies 300 to 800 square feet. Be sure to follow size restrictions, utility separations, and entrance requirements. Hiring a qualified contractor ensures you meet all regulatory requirements because they can pull permits, double-check local code, and gather other skilled pros to work on your suite. 

An in-law suite is a self-contained living space attached to—or detached from—your main home. Expect a bedroom, full bath, and a kitchenette or compact living area. The setup gives relatives privacy, doubles as a potential rental, and can lift your property value. To qualify as a legal dwelling, the suite must meet local building codes and zoning rules.

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.
CONTRACTOR LOOKING OVER HOME DEVELOPMENT
Apr 19, 2025
Apr 19, 2025
Budget for your general contractor’s hourly rate by considering factors such as project scope, fee structure, pricing model, and more.
Outdoor view of the modern house
Jun 16, 2025
Jun 16, 2025
Explore how square footage, room type, home additions, and other common factors affect house renovation costs with our detailed cost guide.
BRIGHT OPEN ATTIC SPACE
Jun 10, 2025
Jun 10, 2025
An in-law suite is a great solution for people who have family visiting often. Explore how much an in-law suite costs and prep to build yours.
white and gray kitchen with butchers block countertop
Apr 8, 2025
Apr 8, 2025
Looking to enhance the warmth and utility of your kitchen? Explore how much a butcher block countertop costs and start your budget here.
built-in outdoor kitchen with grill and sink
Apr 30, 2025
Apr 30, 2025
Budget for outdoor kitchen costs based on factors such as appliances, materials, permits, labor, amenities, kitchen size, customizations, and more.
BLUE TWO STORY HOME
Apr 30, 2025
Apr 30, 2025
Budget for the cost to add a second story based on factors such as size, foundation work, materials, labor, permits, post-construction cleaning, and more.
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