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Addition to existing structure builders in Castro Valley

Avatar for Froyd and Associates, Inc.

Froyd and Associates, Inc.

373 Grapevine Place
5.00(
3
)
Approved Pro

Froyd and Associates, Inc.

373 Grapevine Place
5.00(
3
)
Approved Pro
Customers say: Quick response
10 local quotes requested
3 years of experience

Froyd and Associates s a locally owned and operated company that values honesty and integrity in all aspects of our business. Our dedicated team of professionals have hands on experience, to provide innovative ideas and suggestions tailored to your projects. Our services are customized to your individual needs, paying close attention to the details of each project that we are involved with. Please feel free to contact us today!

"I hired Anthony to do a complete remodel of my interior of my home. We knocked out walls redone all the lighting and cabinetry. He completely floored us with the results. We couldn’t be happier. Did exactly what he said he was going to do and in the time frame he promised! I’m using him on my next project my guest bathroom remodel. He’s honest and came in on budget. Good job to him and his team."

Dan B on August 2025

Froyd and Associates s a locally owned and operated company that values honesty and integrity in all aspects of our business. Our dedicated team of professionals have hands on experience, to provide innovative ideas and suggestions tailored to your projects. Our services are customized to your individual needs, paying close attention to the details of each project that we are involved with. Please feel free to contact us today!

"I hired Anthony to do a complete remodel of my interior of my home. We knocked out walls redone all the lighting and cabinetry. He completely floored us with the results. We couldn’t be happier. Did exactly what he said he was going to do and in the time frame he promised! I’m using him on my next project my guest bathroom remodel. He’s honest and came in on budget. Good job to him and his team."

Dan B on August 2025


North Point Construction and Restoration, Inc.

5114 Port Chicago Hwy B
New on HomeAdvisorNew on HomeAdvisor
Approved Pro

North Point Construction and Restoration, Inc.

5114 Port Chicago Hwy B
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

161 Martin Place
4.71(
7
)
Approved Pro

Universal Construction Company

161 Martin Place
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.

184 Bowling Green Street
3.00(
1
)
Approved Pro

Fixit Construction, Inc.

184 Bowling Green Street
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


Ashbury General Contracting and Engineering

40 12th Street
4.50(
2
)
Approved Pro

Ashbury General Contracting and Engineering

40 12th Street
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

2341 W Ave #133
5.00(
2
)
Approved Pro

AM GENERAL CONTRACTOR

2341 W Ave #133
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


Avatar for Springs Construction Corporation

Springs Construction Corporation

881 Hurlingame Ave
New on HomeAdvisorNew on HomeAdvisor
Approved Pro

Springs Construction Corporation

881 Hurlingame Ave
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.


JJ Builders Inc

14686 Hanover St
New on HomeAdvisorNew on HomeAdvisor
Approved Pro

JJ Builders Inc

14686 Hanover St
New on HomeAdvisorNew on HomeAdvisor
Approved Pro
3 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!

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!


Avatar for Property Pros Construction, Inc.

Property Pros Construction, Inc.

4061 East Castro Valley Boulevard, Suite 454
5.00(
4
)
Approved Pro

Property Pros Construction, Inc.

4061 East Castro Valley Boulevard, Suite 454
5.00(
4
)
Approved Pro
Customers say: Quick response
Recommended by 100% of Angi customers
Recommended by 100% of HomeAdvisor customers
17 years of experience

Property Pros Construction, Inc., proudly serves its customers with pride, integrity and attention to the details that matter most to you. This is one of the many things that set us apart from the rest. We are locally owned and operated. Give us a call today!

"I would highly recommend Mike and his crew They created a new beautiful space in my old 1928 home. Their work was exceptional, and I truly appreciated the hard work, long hours and attention to detail that they all put in on every aspect of the project. They were all very professional, answered all my questions with patience, offered knowledgeable, experienced and skilled suggestions, and always with a smile on their faces and cheerful disposition."

Heidi E on November 2023

Property Pros Construction, Inc., proudly serves its customers with pride, integrity and attention to the details that matter most to you. This is one of the many things that set us apart from the rest. We are locally owned and operated. Give us a call today!

"I would highly recommend Mike and his crew They created a new beautiful space in my old 1928 home. Their work was exceptional, and I truly appreciated the hard work, long hours and attention to detail that they all put in on every aspect of the project. They were all very professional, answered all my questions with patience, offered knowledgeable, experienced and skilled suggestions, and always with a smile on their faces and cheerful disposition."

Heidi E on November 2023


Avatar for ABR Quality Resources Inc

ABR Quality Resources Inc

100 N Hill Blvd
5.00(
2
)
Approved Pro

ABR Quality Resources Inc

100 N Hill Blvd
5.00(
2
)
Approved Pro
22 local quotes requested
4 years of experience

At Hamilton Exteriors, our mission is to serve our community with the highest-value construction solutions. Specializing in roofs, windows, and siding, we bring over 50 years of combined experience to every project. Our skilled team takes pride in meticulous craftsmanship and attention to detail, ensuring every job is done right the first time.

"I scheduled to have someone come give me an estimate for all new windows in our 1950s home with not so great Remodeling work by previous owners. Alex Li promptly met with us and it was a pleasure working with him & his crew throughout the entire process. They were always on time to work, left our home clean of debris & spectacular new JeldWin windows. Helped me with getting Financing as well...Just all around a great experience & highly recommend!"

Renee D on February 2025

At Hamilton Exteriors, our mission is to serve our community with the highest-value construction solutions. Specializing in roofs, windows, and siding, we bring over 50 years of combined experience to every project. Our skilled team takes pride in meticulous craftsmanship and attention to detail, ensuring every job is done right the first time.

"I scheduled to have someone come give me an estimate for all new windows in our 1950s home with not so great Remodeling work by previous owners. Alex Li promptly met with us and it was a pleasure working with him & his crew throughout the entire process. They were always on time to work, left our home clean of debris & spectacular new JeldWin windows. Helped me with getting Financing as well...Just all around a great experience & highly recommend!"

Renee D on February 2025

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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.

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    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.