How much do addition contractors typically cost?
- Thornton, California Average$11,125
- Typical Range$6,750 - $15,500
- Low End - High End$6,500 - $18,000

Find a Custom Home Builder, Kitchen - Remodel, Addition to Existing Structure - Build , and 7 more
"Doble construction did a professional job building my shed. It is the most beautiful she shed I've seen. Quality build, professional workmanship, finished the project before the deadline. I wish all contractors were as great to work with. Would definitely use Doble construction again and highly recommend."
Ilena F. in November 2018

Quality finishes, tile, wood, marble, quartz, travertine, stone
"Michael and team did such an amazing job on our bathroom remodel. They took our tiny, dysfunctional bathroom and turned it into a true master bathroom oasis in a short amount of time during the holiday season. When they had the space down to the studs, Michael sat down with us and discussed in detail the best possible use of the space and we couldn’t be happier with our final decision after going through the options. Michael was great at communicating and we still stay in touch to this day, which we truly appreciate. Great team who does great work and I will absolutely be giving Waters Construction a call for any and all future home renovations. I’ll let the pictures do the rest of the talking."
E37772FA2E71CBB442874E8BC303B297B35A3863D80871CF215EE1A32E2506D8 7. in November 2025
"I hired this company to renovate a garage that was converted into a family room approx 60 years ago by my parents. The space included a shower, toilet, in small area. After inheriting the house, I hired this company to update the bathroom, which was the original construction 1955, only a cement finish. Additionally, he transformed the family room into a bedroom for myself and added a sink vanity and mirror, installed new doors, and laid tile in the vanity area, bthrm, & shower stall. Before & after pictures will be posted, noting that the before pictures depict the space when it was rented by someone else. Company owner Raul, demonstrated exceptional expertise and provided valuable feedback throughout the project. His crew was outstanding, I am thoroughly satisfied with the results, considering myself fortunate to have found such a skilled contractor. Thank you very much Twin Home Solutions Inc. I'll have you back for more updates later. Very reasonably priced too!"
67641A37CE5A6F0177FAEED93AD5F7BDA2157C84E985728187A667B79A609659 E. in March 2026
In business since 2019
About us: "30+ years of experience! JL construction & caulking. Our mission is to be a provider that brings back the personal touch with our customers. We will build a relationship that will last a lifetime after you see our quality work. As a locally owned and operated business, we feel invested in our clients and constantly strive for customer satisfaction. Call or message us to schedule an estimate today!"
About us: "Over 30 years of experience. One call does it all!!"

In business since 2023
General Contractor, Client Focused Custom Home, ADU and Outdoor Living Spaces. We offer Design/Build packages with transparent budgeting and clear communication., Communication & Client Relations , and 2 more
About us: "LaFargue General 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. We have 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., with a 3 hour minimum on service requests. home as if it were our own. Our services are customized to the individual"

About us: "A+ BBB Rated Sahner Construction has been in business for 10 years. We have provided remodels, additions and full builds throughout the central Valley. With over 20 years of experience in the home building industry, we know what is important to our customers and we deliver on our commitments. Your project will be handled with top in class quality, on schedule and within budget."

In business since 2014
Handyman Services, Commerical & Residential, Kitchen And Bathroom Remodels, (ADU) Additional Dwelling Units, Drywall, Exterior And Exterior Painting, Water Heater Installation, Roofing, Patios, Arbors, Decks.
About us: "Welcome to Caldwell Construction Inc. We are family owned and operated. Since opening our doors in 2014, we’ve remained committed to understanding each client’s unique project needs and delivering work that earns their complete satisfaction. As an industry leader, we take a comprehensive, detail‑driven approach that allows us to provide a wide range of high‑quality construction services. OUR SERVICES -Full Kitchen And Bathroom Remodels -ADU Additional Dwelling Unit -Interior And Exterior Painting -Arbors And Decks -Drywall -Air Conditioner Installation -Water Heater Installation -Cabinet Installation -Roofing -Building Maintenance -Handyman Services"

About us: "Hello everybody my name is will orozco ceo of w orozco construction inc we are here to help you with your house project ADU Remodeling new construction we are a company what we staring the company from bottom we know all about construction the main goal is keep all the costumer happy with all the construction projects clean and safe"
HomeAdvisor makes it easy to connect with pros near you. You can read reviews, get quotes and book appointments all in one place.
Depending on the type of project, you may find subtle differences in the hiring process. Here’s a look at task-specific advice.
You can use HomeAdvisor to help evaluate a contractor’s qualifications. We put pros through a screening process, and award badges to high-performing contractors. You can find these badges on a pro’s HomeAdvisor profile, and sometimes, his or her website.
Your research doesn’t stop here. Once you’ve found a few prospective companies, make an call to ask a few questions about work history, licensure and more:
In most cases, the responses you get to these three questions will give you a very good idea of the right pro for your project. If you have more than one front-runner, these additional questions can help you narrow it down.
Any good contractor will answer these questions, and most will appreciate dealing with a client that takes such an active interest in finding good service. On the other hand, if a contractor gives you a hard time with these questions, you probably want to find someone else.
Thornton Addition & Remodeling Contractors are rated 5.0 out of 5 based on 16 reviews of 16 pros.
The HomeAdvisor Community Rating is an overall rating based on verified reviews and feedback from our community of homeowners that have been connected with service professionals. See individual business pages for full, detailed reviews.
If you're looking for Build an Addition Contractors that serve a different city in California, here are some popular suggestions:
What best describes this project?
Find out how HomeAdvisor can help your business