Top-rated addition to existing structure builders.

Get matched with top addition to existing structure builders in your area

Enter your zip and get matched with up to 3 pros

Matching on HomeAdvisor

Share some details icon
Share some details about your home project.
Match with local pros icon
Within moments, match with highly-rated local pros.
Compare quotes icon
Compare quotes and choose the best pro for the job.

Addition to existing structure builders in Sebastopol

Avatar for BCR Construction
BCR Construction
889 Jennings Ave
5.00(
1
)
Approved Pro
BCR Construction
889 Jennings Ave
5.00(
1
)
Approved Pro
Customers say: Quick response
Recommended by 100% of Angi customers
Recommended by 100% of HomeAdvisor customers
6 years of experience

BCR 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.

""

Stanley C on March 2022

BCR 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.

""

Stanley C on March 2022


Avatar for Tanoak Construction, LLC
Tanoak Construction, LLC
122 Calistoga Road, Unit 194
3.67(
3
)
Approved Pro
Tanoak Construction, LLC
122 Calistoga Road, Unit 194
3.67(
3
)
Approved Pro
Customers say: Quick response
8 years of experience
Free onsite estimate

I have more than 35 years' of residential, commercial and industrial experience and I pride my company on reliability, great communication, integrity, and quality work. I will do my best to keep you as educated as we can on your particular project. I look forward to earning your business!

"We recently had our bathroom remodeled by Tanoak Construction and we are extremely satisfied with the quality of workmanship. Gant Bowman and Dave Bowman were always available to answer any questions we had and were very transparent throughout the entire process. Finding a local contractor was difficult, but Tanoak Construction made the process easy and stress-free. They were clean, very respectful while in our home, and gave great advice. Every subcontractor they brought in was also great to work with. We highly recommend them to anyone in the Sonoma County area who needs remodeling work done."

Martin B on September 2023

I have more than 35 years' of residential, commercial and industrial experience and I pride my company on reliability, great communication, integrity, and quality work. I will do my best to keep you as educated as we can on your particular project. I look forward to earning your business!

"We recently had our bathroom remodeled by Tanoak Construction and we are extremely satisfied with the quality of workmanship. Gant Bowman and Dave Bowman were always available to answer any questions we had and were very transparent throughout the entire process. Finding a local contractor was difficult, but Tanoak Construction made the process easy and stress-free. They were clean, very respectful while in our home, and gave great advice. Every subcontractor they brought in was also great to work with. We highly recommend them to anyone in the Sonoma County area who needs remodeling work done."

Martin B on September 2023


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


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


Reichert Building Solutions
11 Friendly Lane
5.00(
4
)
Approved Pro
Reichert Building Solutions
11 Friendly Lane
5.00(
4
)
Approved Pro
Customers say: Quick response
Recommended by 100% of Angi customers
Recommended by 100% of HomeAdvisor customers
9 years of experience

With years of experience serving the area, we are your solution for all your (PWC) needs. We take great pride in our extreme professionalism, timeliness and superior customer service on every job. We make sure to develop a lasting relationship so that the next time service is needed there will be no question on who to call. Check out our 5 star reviews from happy customers! Call us today so we can discuss your needs and make a plan that fits your budget. Satisfaction guaranteed!

"they are great"

Jenny H on July 2024

With years of experience serving the area, we are your solution for all your (PWC) needs. We take great pride in our extreme professionalism, timeliness and superior customer service on every job. We make sure to develop a lasting relationship so that the next time service is needed there will be no question on who to call. Check out our 5 star reviews from happy customers! Call us today so we can discuss your needs and make a plan that fits your budget. Satisfaction guaranteed!

"they are great"

Jenny H on July 2024


Alpha Omega Builders
4485 Hargrave Avenue
4.21(
9
)
Approved Pro
Alpha Omega Builders
4485 Hargrave Avenue
4.21(
9
)
Approved Pro
Customers say: Quality work
20 years of experience
Free onsite estimate

Alpha Omega Builders is your only stop for all of your building needs. We take pride in providing you with the best work available in the area. We treat your home like it was our own.

"On time, knowledgeable, fit us into his schedule. Had a small lingering issue and he came back quickly to fix the problem. A pleasure to work with."

Mary B on September 2017

Alpha Omega Builders is your only stop for all of your building needs. We take pride in providing you with the best work available in the area. We treat your home like it was our own.

"On time, knowledgeable, fit us into his schedule. Had a small lingering issue and he came back quickly to fix the problem. A pleasure to work with."

Mary B on September 2017


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
18 years of experience
Free onsite estimate

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.


Big River Builders, Inc.
5510 Skylane Boulevard, Suite 203
4.50(
2
)
Approved Pro
Big River Builders, Inc.
5510 Skylane Boulevard, Suite 203
4.50(
2
)
Approved Pro
Customers say: Quick response
Recommended by 100% of Angi customers
Recommended by 100% of HomeAdvisor customers
16 local quotes requested

BIG RIVER BUILDERS INC offers 40 years experience and the best customer service. We are here to build relationships with our customers and communities. BIG RIVER BUILDERS INC is a leader providing our customers with the highest quality products and craftsmanship in an honest, efficient, and professional way. We believe in building trust, treating every project with the utmost integrity and exceeding expectations. We look forward to working with you!

"The employees were great. A couple of days there was only 1 man on the job due to illness. The company did not replace him, so the 1 man had to work alone, slowing down the completion of the project. Art and Johnny were great to work with. Communication with the office was a little lacking, but overall we are happy with the work."

Bruce J on September 2020

BIG RIVER BUILDERS INC offers 40 years experience and the best customer service. We are here to build relationships with our customers and communities. BIG RIVER BUILDERS INC is a leader providing our customers with the highest quality products and craftsmanship in an honest, efficient, and professional way. We believe in building trust, treating every project with the utmost integrity and exceeding expectations. We look forward to working with you!

"The employees were great. A couple of days there was only 1 man on the job due to illness. The company did not replace him, so the 1 man had to work alone, slowing down the completion of the project. Art and Johnny were great to work with. Communication with the office was a little lacking, but overall we are happy with the work."

Bruce J on September 2020


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
217 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!


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
241 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

...
Showing 1-10 of 992

Addition to existing structure building services FAQs

How far you can push a room depends on the structure you choose. A cantilevered bump-out can extend 24 inches before building codes require its own footing or foundation. Anything longer needs engineered support and a permit. Check local codes or consult with a structural professional before finalizing plans to ensure your design remains safe and compliant.

Most bump-outs are completed within one to four weeks, even with minimal electrical, plumbing, or HVAC work. Their compact size means less demolition, simpler inspections, and fewer weather-related delays compared to a full-scale addition. Your contractor can provide a more precise timeline once they have determined the scope, materials, and permit schedule, but plan on having the extra square footage ready in approximately a month.

The 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.
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.
small bathroom that has been updated in a remodel
Apr 29, 2025
Apr 29, 2025
Budget for the cost to remodel a small bathroom based on factors such as required fixtures, bathroom size, labor, remodel type, site prep, and more.
guest house in the backyard
Apr 27, 2025
Apr 27, 2025
Need to build a guest house? Here’s how much it costs, what factors affect cost, and what to expect.
Kitchen view leading into dining area
Apr 28, 2025
Apr 28, 2025
Use this guide to budget for bump-out addition costs based on factors such as room size, room type, labor, finishes, permits, and more.
House roof with nice window
Apr 28, 2025
Apr 28, 2025
Budget for dormer addition costs based on factors such as roof type, framing, customizations, reinforcement, cladding, labor, and more.
Share project details to get started.