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Find Addition to existing structure builders in Castro Valley

Avatar for UNITED C CONSTRUCTION, INC

UNITED C CONSTRUCTION, INC

5.00(
3
)
Approved Pro

UNITED C CONSTRUCTION, INC

5.00(
3
)
Approved Pro
Customers say: Quick response
1 years of experience
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!

"Updating our home was a dream we have had for years. But finding a good contractor in Bay Area was so difficult, that we almost gave up. We were introduced to United C Construction by our architect(who we also love!) It was exhausting trying to find someone trustworthy and not overpriced. We had luck of working with Osmar which during the project we had clear communication, expectation of setting, professionalism and superior craftsmanship. He walked us through every step of the way, and helped problem solve tough permitting and structural issues in Berkeley!"

Shelby R on September 2024

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!

"Updating our home was a dream we have had for years. But finding a good contractor in Bay Area was so difficult, that we almost gave up. We were introduced to United C Construction by our architect(who we also love!) It was exhausting trying to find someone trustworthy and not overpriced. We had luck of working with Osmar which during the project we had clear communication, expectation of setting, professionalism and superior craftsmanship. He walked us through every step of the way, and helped problem solve tough permitting and structural issues in Berkeley!"

Shelby R on September 2024


Ashbury General Contracting and Engineering

4.50(
2
)
Approved Pro

Ashbury General Contracting and Engineering

4.50(
2
)
Approved Pro
Customers say: Terrific value
Recommended by 100% of Angi customers
Recommended by 100% of HomeAdvisor customers
35 years of experience

Mon-Fri 7a-5pm Fully integrated company. All work is done in-house by employees not sub-contractors. 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 forwards to earning your business! Book with us online or feel free to give us a call today!

"Great work for a great price."

Paul H on March 2023

Mon-Fri 7a-5pm Fully integrated company. All work is done in-house by employees not sub-contractors. 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 forwards to earning your business! Book with us online or feel free to give us a call today!

"Great work for a great price."

Paul H on March 2023


AM GENERAL CONTRACTOR

5.00(
2
)
Approved Pro

AM GENERAL CONTRACTOR

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

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

"What ever he plans for the project,He compleat that.He is honest and fair.I will refer him to my friends and family."

Mina R on November 2020

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

"What ever he plans for the project,He compleat that.He is honest and fair.I will refer him to my friends and family."

Mina R on November 2020


North Point Construction and Restoration, Inc.

New on HomeAdvisorNew on HomeAdvisor
Approved Pro

North Point Construction and Restoration, Inc.

New on HomeAdvisorNew on HomeAdvisor
Approved Pro
8 years of experience
Free onsite estimate

At North Point Construction and Restoration, Inc., we pride our company on reliability, great communication, integrity, and quality work that customers can believe in. 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 and working with you! 20 years of experience.

At North Point Construction and Restoration, Inc., we pride our company on reliability, great communication, integrity, and quality work that customers can believe in. 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 and working with you! 20 years of experience.


Universal Construction Company

4.71(
7
)
Approved Pro

Universal Construction Company

4.71(
7
)
Approved Pro
Customers say: Quick response
Recommended by 100% of Angi customers
Recommended by 100% of HomeAdvisor customers
45 years of experience

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 general contractor and home improvement services that are customizable to each individual project. We specialize in additions and bathroom 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!

"He is very good, communicates well, and he is there when he says he will be and very thorough! I liked doing business with him! He explains everything that he will do before he does the job and he listens to my suggestions."

Marilyn B on June 2019

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 general contractor and home improvement services that are customizable to each individual project. We specialize in additions and bathroom 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!

"He is very good, communicates well, and he is there when he says he will be and very thorough! I liked doing business with him! He explains everything that he will do before he does the job and he listens to my suggestions."

Marilyn B on June 2019


Avatar for Fixit Construction, Inc.

Fixit Construction, Inc.

3.00(
1
)
Approved Pro

Fixit Construction, Inc.

3.00(
1
)
Approved Pro
Customers say: Terrific value
Recommended by 100% of Angi customers
Recommended by 100% of HomeAdvisor customers
11 years of experience

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! Book with us online or feel free to give us a call today!

"They were professional and completed the project on time."

Elizabete T on September 2016

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! Book with us online or feel free to give us a call today!

"They were professional and completed the project on time."

Elizabete T on September 2016


Avatar for Springs Construction Corporation

Springs Construction Corporation

New on HomeAdvisorNew on HomeAdvisor
Approved Pro

Springs Construction Corporation

New on HomeAdvisorNew on HomeAdvisor
Approved Pro
66 years of experience
Free onsite estimate

Since 1959, Springs Construction has built its reputation on fine craftsmanship, technical expertise and solid project management.We take a proactive, client driven approach to every one of our projects, exceeding our customers vision for their homes. We want you to feel comfortable and safe during the disruption and enjoy your home for years to come.

Since 1959, Springs Construction has built its reputation on fine craftsmanship, technical expertise and solid project management.We take a proactive, client driven approach to every one of our projects, exceeding our customers vision for their homes. We want you to feel comfortable and safe during the disruption and enjoy your home for years to come.


Avatar for My Construction Group

My Construction Group

4.82(
182
)
Approved Pro

My Construction Group

4.82(
182
)
Approved Pro
Super Service Award
Customers say: Terrific value
Recommended by 97% of Angi customers
Recommended by 97% of HomeAdvisor customers
87 local quotes requested

We Stand Behind Our Work, Quality, Brand and Commitment Located in San Jose, My Construction Group is your one source for construction needs, and quality design. Our experienced team and project managers will listen and help you focus on your goals, create an innovative design or renovate on matching your vision, and take all the worry and stress out of the process for you. Our team of professional contractors and project managers oversee and manage each project efficiently through on-site preparation, on-time scheduling, accurate budgeting and cost management. In addition, our goal is to assure quality building services while maintaining consistent client communication throughout each project. My Construction Group is a leading home remodeling company, interested in making the best and most remarkable construction in California. Please click or copy the link to see our new construction project https://youtu.be/1teqJZQhzBA

"Our experience is identical to what other reviewers shared. And yes, you should run from this company as fast as you can. Do not buy what Abraham shared that the payment must be made when the inspection is passed. Check the Business and Professions code yourself, the payment only needs to be made when the job is completed. It is very COMMON that the job is not even done or poorly performed even the inspection is passed. Here are the issues that multiple families including us run into with this company:: The project was delayed for over 9 months. No one manages the job. He often employs young men from his own Jewish community. They are enthusiastic but had no prior experience. The worse part is that they don't get paid. Two of them even set up a new construction business knowing Abraham will never pay them. Subcontractors can put your house on lien also. Many reviews you see on Yelp, Google, Angi are NOT genuine. Even the references are fake with hindsight, we were given 2 references. One reference shared the exact same accent as the PM. The other reference was initially happy with their work, but then reached out to us and shared a similar horror story with them like what we experienced. You will lose a lot of $$$ on materials as the subcontractors will somehow leave a thousand dollars worth of quartz at home. Maybe they want to compensate for the money Abraham owed them? Let me tell you, reordering materials is not fun."

Jaqueline R on May 2025

We Stand Behind Our Work, Quality, Brand and Commitment Located in San Jose, My Construction Group is your one source for construction needs, and quality design. Our experienced team and project managers will listen and help you focus on your goals, create an innovative design or renovate on matching your vision, and take all the worry and stress out of the process for you. Our team of professional contractors and project managers oversee and manage each project efficiently through on-site preparation, on-time scheduling, accurate budgeting and cost management. In addition, our goal is to assure quality building services while maintaining consistent client communication throughout each project. My Construction Group is a leading home remodeling company, interested in making the best and most remarkable construction in California. Please click or copy the link to see our new construction project https://youtu.be/1teqJZQhzBA

"Our experience is identical to what other reviewers shared. And yes, you should run from this company as fast as you can. Do not buy what Abraham shared that the payment must be made when the inspection is passed. Check the Business and Professions code yourself, the payment only needs to be made when the job is completed. It is very COMMON that the job is not even done or poorly performed even the inspection is passed. Here are the issues that multiple families including us run into with this company:: The project was delayed for over 9 months. No one manages the job. He often employs young men from his own Jewish community. They are enthusiastic but had no prior experience. The worse part is that they don't get paid. Two of them even set up a new construction business knowing Abraham will never pay them. Subcontractors can put your house on lien also. Many reviews you see on Yelp, Google, Angi are NOT genuine. Even the references are fake with hindsight, we were given 2 references. One reference shared the exact same accent as the PM. The other reference was initially happy with their work, but then reached out to us and shared a similar horror story with them like what we experienced. You will lose a lot of $$$ on materials as the subcontractors will somehow leave a thousand dollars worth of quartz at home. Maybe they want to compensate for the money Abraham owed them? Let me tell you, reordering materials is not fun."

Jaqueline R on May 2025


Avatar for Cal Green Remodeling Inc.

Cal Green Remodeling Inc.

5.00(
33
)
Approved Pro

Cal Green Remodeling Inc.

5.00(
33
)
Approved Pro
Customers say: Quick response
Recommended by 90% of Angi customers
Recommended by 90% of HomeAdvisor customers
11 local quotes requested

Home Remodeling and Commercial Renovation. From custom kitchens to concrete floors we do it all and our experienced professionals can help you figure out what products are right for you. We offer industrial grade finishes that can handle excessive traffic, as well as fine finishes for your home.

"After months of planning, we chose Aly to remodel our kitchen and living room and we're so glad we did. From the initial consultation to the final walk-through, the process was seamless. The team was respectful of our home and incredibly friendly. We absolutely love our new space and highly recommend Aly and his team at Cal Green Remodeling."

Albert A on June 2025

Home Remodeling and Commercial Renovation. From custom kitchens to concrete floors we do it all and our experienced professionals can help you figure out what products are right for you. We offer industrial grade finishes that can handle excessive traffic, as well as fine finishes for your home.

"After months of planning, we chose Aly to remodel our kitchen and living room and we're so glad we did. From the initial consultation to the final walk-through, the process was seamless. The team was respectful of our home and incredibly friendly. We absolutely love our new space and highly recommend Aly and his team at Cal Green Remodeling."

Albert A on June 2025


Avatar for Tech Line Construction, Inc.

Tech Line Construction, Inc.

5.00(
8
)
Approved Pro

Tech Line Construction, Inc.

5.00(
8
)
Approved Pro
Customers say: Quick response
Recommended by 100% of Angi customers
Recommended by 100% of HomeAdvisor customers
14 local quotes requested

At Tech Line Construction, we take immense pride in our long built reputation for building stunning, efficient home improvement projects that mirror the unique style and elegance of the people who live in them. Tech Line Construction has a standing passion for the intricacies and artistry involved with residential home improvement . With team members over 15 years in the industry and a wealth of experience, Tech Line Construction is the premier choice for those looking to craft their dreams into a reality. Our focus is every little detail and we take great pride in setting the bar for the highest standards in quality craftsmanship and proactive problem-solving. Don't hesitate to contact us today for a free consultation TECHLINECONSTRUCTIONDESIGN.COM Office@techlinconstruction.info (510)798-5869

"We had a great experience working with Tech Line Construction. They did a complete remodel of our kitchen, bathroom, and flooring. The whole process was very smooth and we are extremely happy with the results. Cooking in our new kitchen is a joy and we can't wait to entertain guests in our beautiful space."

Patricia M D on November 2022

At Tech Line Construction, we take immense pride in our long built reputation for building stunning, efficient home improvement projects that mirror the unique style and elegance of the people who live in them. Tech Line Construction has a standing passion for the intricacies and artistry involved with residential home improvement . With team members over 15 years in the industry and a wealth of experience, Tech Line Construction is the premier choice for those looking to craft their dreams into a reality. Our focus is every little detail and we take great pride in setting the bar for the highest standards in quality craftsmanship and proactive problem-solving. Don't hesitate to contact us today for a free consultation TECHLINECONSTRUCTIONDESIGN.COM Office@techlinconstruction.info (510)798-5869

"We had a great experience working with Tech Line Construction. They did a complete remodel of our kitchen, bathroom, and flooring. The whole process was very smooth and we are extremely happy with the results. Cooking in our new kitchen is a joy and we can't wait to entertain guests in our beautiful space."

Patricia M D on November 2022

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FAQs for addition to existing structure building service projects in Castro Valley, 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 Castro Valley, 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.