Top-rated second story addition builders.

Get matched with top second story addition builders in Castro Valley, CA

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.

Second story addition builders in Castro Valley

Avatar for Plan Perfect Remodeling

Plan Perfect Remodeling

Bay Area
5.00(
11
)
•Approved Pro

Plan Perfect Remodeling

Bay Area
5.00(
11
)
•Approved Pro
Customers say: Quick response
672 local quotes requested
3 years of experience

At Plan Perfect Remodeling, WE SPECIALIZE IN KITCHEN AND BATH REMODELS but our expertise extends to all aspects of home renovation. Whether you're considering a full home makeover or simply want to refresh specific areas, we're here to bring your vision to life. Not sure where to start? Schedule a complimentary, in-home design consultation with us. Consultation includes 3-D design presentation. Our team will provide expert guidance and tailored recommendations to help you make the most of your space. Let's work together to create a home that reflects your style and exceeds your expectations.

"Fantastic team of honest workers. They took care of every problem and logistics in a professional and timely manner. Extremely happy with the final product, would absolutely refer."

Dominic E on April 2024

At Plan Perfect Remodeling, WE SPECIALIZE IN KITCHEN AND BATH REMODELS but our expertise extends to all aspects of home renovation. Whether you're considering a full home makeover or simply want to refresh specific areas, we're here to bring your vision to life. Not sure where to start? Schedule a complimentary, in-home design consultation with us. Consultation includes 3-D design presentation. Our team will provide expert guidance and tailored recommendations to help you make the most of your space. Let's work together to create a home that reflects your style and exceeds your expectations.

"Fantastic team of honest workers. They took care of every problem and logistics in a professional and timely manner. Extremely happy with the final product, would absolutely refer."

Dominic E on April 2024

Avatar for Geico Builders

Geico Builders

1901 Harrison Street
5.00(
25
)
•Approved Pro

Geico Builders

1901 Harrison Street
5.00(
25
)
•Approved Pro
Customers say: Quick response
Recommended by 100% of Angi customers
Recommended by 100% of HomeAdvisor customers
1707 local quotes requested

Geico Builders specializes in meeting your expectations before, during, and after the project is complete. Our most upstanding quality is our accountability--you can expect us to own the work we complete for your home. Of course, we know accountability means nothing without proof, which is why we are happy to offer a 2-year workmanship warranty to all of our clients. This is a rare quality for this industry, but we wanted to prove to you that we stand by our craftsmanship through our home remodeling construction services. Every Crew at Geico Builders has been professionally trained and will treat your home with integrity and respect.

"We are glad we went with Geico Builders for a full master bath remodel. They were very easy to work with everything went as planned and we were very happy with the results. Diane was our main choice, she knew exactly how to invasion perfect layout of our bathroom remodel. They set up a group chat with everyone to coordinate and they communicated very well. Inspections were schedule very quickly, and they forwarded us the results & paperwork as soon as they received it. Alex, the designer, was helpful in helping to putt together our design and vendor recommendations. She quickly responded to feedback & updates to our design, and she even worked through her vacation on our project. When on of the vendors got our order correctly, the Geico Builders team worked with them to quickly rectify the issue. During construction, the foreman, Tony was very well organized and good to work with. His team was friendly, careful, and they kept the place as clean as they could. They follow up with us throughout construction to ensure that every detail of the construction was built to what we wanted."

Michael C on September 2025

Geico Builders specializes in meeting your expectations before, during, and after the project is complete. Our most upstanding quality is our accountability--you can expect us to own the work we complete for your home. Of course, we know accountability means nothing without proof, which is why we are happy to offer a 2-year workmanship warranty to all of our clients. This is a rare quality for this industry, but we wanted to prove to you that we stand by our craftsmanship through our home remodeling construction services. Every Crew at Geico Builders has been professionally trained and will treat your home with integrity and respect.

"We are glad we went with Geico Builders for a full master bath remodel. They were very easy to work with everything went as planned and we were very happy with the results. Diane was our main choice, she knew exactly how to invasion perfect layout of our bathroom remodel. They set up a group chat with everyone to coordinate and they communicated very well. Inspections were schedule very quickly, and they forwarded us the results & paperwork as soon as they received it. Alex, the designer, was helpful in helping to putt together our design and vendor recommendations. She quickly responded to feedback & updates to our design, and she even worked through her vacation on our project. When on of the vendors got our order correctly, the Geico Builders team worked with them to quickly rectify the issue. During construction, the foreman, Tony was very well organized and good to work with. His team was friendly, careful, and they kept the place as clean as they could. They follow up with us throughout construction to ensure that every detail of the construction was built to what we wanted."

Michael C on September 2025

Avatar for Unique Home Design & Remodeling

Unique Home Design & Remodeling

303 Twin Dolphin Dr.
New on HomeAdvisorNew on HomeAdvisor
•Approved Pro

Unique Home Design & Remodeling

303 Twin Dolphin Dr.
New on HomeAdvisorNew on HomeAdvisor
•Approved Pro
1950 local quotes requested
42 years of experience

Unique Home Design & Remodeling is a leader in providing value-added construction services to our customers by creating a successful partnership throughout the construction process. Our pledge is to establish lasting relationships with our customers by exceeding their expectations and gaining their trust through exceptional performance by every member on our construction team. Unique Home Design & Remodeling's mission is to accomplish full customer satisfaction in every area possible from color selection to project completion. Unique Home Design & Remodeling's main focus is to provide our future clients with a professional home improvement experience. We vow to our customers with the highest level of quality construction services at fair market and competitive prices. To ensure the longevity of our company through repeat and referral business achieved by customer satisfaction in all areas including timeliness, attention to detail and service-minded attitudes.

Unique Home Design & Remodeling is a leader in providing value-added construction services to our customers by creating a successful partnership throughout the construction process. Our pledge is to establish lasting relationships with our customers by exceeding their expectations and gaining their trust through exceptional performance by every member on our construction team. Unique Home Design & Remodeling's mission is to accomplish full customer satisfaction in every area possible from color selection to project completion. Unique Home Design & Remodeling's main focus is to provide our future clients with a professional home improvement experience. We vow to our customers with the highest level of quality construction services at fair market and competitive prices. To ensure the longevity of our company through repeat and referral business achieved by customer satisfaction in all areas including timeliness, attention to detail and service-minded attitudes.

Avatar for Cal Green Remodeling

Cal Green Remodeling

1400 Coleman Ave, Unit F14-2
5.00(
14
)
•Approved Pro

Cal Green Remodeling

1400 Coleman Ave, Unit F14-2
5.00(
14
)
•Approved Pro
Customers say: Quick response
Recommended by 100% of Angi customers
Recommended by 100% of HomeAdvisor customers
769 local quotes requested

Welcome to Cal Green Remodeling. We do our best to take the stress out of home remodeling, working directly with our clients to make sure they understand the process, options available, and budget. Our goal is to make your project everything you dreamt it would be. 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. Contact us today for a free estimate, we look forward to hearing from you. Website - https://calgreenremodeling.com/ Phone - 800-803-9927

"We were looking to remodel our kitchen or bath for a few years. We kept getting estimates from different companies and always felt the price was off or the person was not a good fit. Then, finally, we met Shai with Cal Green Remodeling. What a great guy! He is very upfront and honest about what we can expect in terms of cost and work flow. Because of his honest approach, we hired him. We felt he gave us the good and bad and how to resolve the bad as well. In the end, the process was fairly smooth, and the few hick-ups we had, for example, the city and their permit process, were well explained to us at the beginning, so we were ready. Our kitchen or bath looks amazing, and I plan to work with Cal Green Remodeling again. Thanks Shai!"

Albert R on December 2023

Welcome to Cal Green Remodeling. We do our best to take the stress out of home remodeling, working directly with our clients to make sure they understand the process, options available, and budget. Our goal is to make your project everything you dreamt it would be. 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. Contact us today for a free estimate, we look forward to hearing from you. Website - https://calgreenremodeling.com/ Phone - 800-803-9927

"We were looking to remodel our kitchen or bath for a few years. We kept getting estimates from different companies and always felt the price was off or the person was not a good fit. Then, finally, we met Shai with Cal Green Remodeling. What a great guy! He is very upfront and honest about what we can expect in terms of cost and work flow. Because of his honest approach, we hired him. We felt he gave us the good and bad and how to resolve the bad as well. In the end, the process was fairly smooth, and the few hick-ups we had, for example, the city and their permit process, were well explained to us at the beginning, so we were ready. Our kitchen or bath looks amazing, and I plan to work with Cal Green Remodeling again. Thanks Shai!"

Albert R on December 2023

Avatar for Accurate Home Remodeling

Accurate Home Remodeling

52 Golf Club Rd #144
New on HomeAdvisorNew on HomeAdvisor
•Approved Pro

Accurate Home Remodeling

52 Golf Club Rd #144
New on HomeAdvisorNew on HomeAdvisor
•Approved Pro
479 local quotes requested

Accurate Home Remodeling services the San Francisco Bay Area. Driven by years of accumulated experience, we’re a fully licensed, bonded, and insured company offering full construction services ranging from kitchen & bathroom remodeling, exteriors, home additions, and much more. Your assigned estimating designer will sit down with you during the complimentary consultation to help you establish an optimal layout and overall vision for the project at hand. Following the consultation, we can create 3D renders to allow you to preview your newly renovated space. Our approach is to work side by side with you to select material at the best locations around the bay area to make your concepts become a reality. Call or 'click' for a FREE estimate today!

Accurate Home Remodeling services the San Francisco Bay Area. Driven by years of accumulated experience, we’re a fully licensed, bonded, and insured company offering full construction services ranging from kitchen & bathroom remodeling, exteriors, home additions, and much more. Your assigned estimating designer will sit down with you during the complimentary consultation to help you establish an optimal layout and overall vision for the project at hand. Following the consultation, we can create 3D renders to allow you to preview your newly renovated space. Our approach is to work side by side with you to select material at the best locations around the bay area to make your concepts become a reality. Call or 'click' for a FREE estimate today!

Avatar for Dream Build Services LLC

Dream Build Services LLC

3654 Thornton Avenue #530
5.00(
7
)
•Approved Pro

Dream Build Services LLC

3654 Thornton Avenue #530
5.00(
7
)
•Approved Pro
Customers say: Quick response
Recommended by 100% of Angi customers
Recommended by 100% of HomeAdvisor customers
1229 local quotes requested

We specialize in all phases of remodeling for your home, business, bathrooms, kitchens, finishing basements, and more! We offer a diverse range of services tailored to meet the unique needs of every customer. We take a personalized approach to each project. We work closely with our clients to understand their vision, preferences, and budgetary requirements. We strive to exceed expectations by delivering exceptional service, great quality work, and professionalism on every job. Read more below on all the services we offer and contact us with any questions or to schedule a free estimate today!

"Dylan and team did a great job. Crew is humble and patient and punctual. Dylan is responsive with queries."

Gaurav S on July 2025

We specialize in all phases of remodeling for your home, business, bathrooms, kitchens, finishing basements, and more! We offer a diverse range of services tailored to meet the unique needs of every customer. We take a personalized approach to each project. We work closely with our clients to understand their vision, preferences, and budgetary requirements. We strive to exceed expectations by delivering exceptional service, great quality work, and professionalism on every job. Read more below on all the services we offer and contact us with any questions or to schedule a free estimate today!

"Dylan and team did a great job. Crew is humble and patient and punctual. Dylan is responsive with queries."

Gaurav S on July 2025

Avatar for My Construction Group

My Construction Group

2011 O'Toole Ave
4.83(
183
)
•Approved Pro

My Construction Group

2011 O'Toole Ave
4.83(
183
)
•Approved Pro
Customers say: Terrific value
Recommended by 97% of Angi customers
Recommended by 97% of HomeAdvisor customers
3275 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 Elite Custom Pools Inc

Elite Custom Pools Inc

4750 Almaden Expy
4.03(
29
)
•Approved Pro

Elite Custom Pools Inc

4750 Almaden Expy
4.03(
29
)
•Approved Pro
Customers say: True professional
1312 local quotes requested
Free onsite estimate

We are Pool & Spa specialists, We provide Installation and remodel for in-ground pools, We offer; Full service Chemical service Chem-plus service, Installation of the newest pool equipment on the market Automation Pool Pumps Pool Filters Pool Cleaners Heaters Salt systems We specialize in; Energy efficient pool equipment that saves the customers up to 90% on electricity, We guarantee CRYSTAL CLEAR WATER in 7 days, We have 15 years experience, We are; CPO- certified pool operator, CPI- certified pool inspector, CAEI- certified aquatic equipment installers We will be happy to answer any questions you might have about your swimming pool

"probably the best contractors i have ever had here. pool was resurfaced and re grouted in a timely manor. all workers were fast and very polite"

sunnyvale m on November 2021

We are Pool & Spa specialists, We provide Installation and remodel for in-ground pools, We offer; Full service Chemical service Chem-plus service, Installation of the newest pool equipment on the market Automation Pool Pumps Pool Filters Pool Cleaners Heaters Salt systems We specialize in; Energy efficient pool equipment that saves the customers up to 90% on electricity, We guarantee CRYSTAL CLEAR WATER in 7 days, We have 15 years experience, We are; CPO- certified pool operator, CPI- certified pool inspector, CAEI- certified aquatic equipment installers We will be happy to answer any questions you might have about your swimming pool

"probably the best contractors i have ever had here. pool was resurfaced and re grouted in a timely manor. all workers were fast and very polite"

sunnyvale m on November 2021

Avatar for Skytech Builders

Skytech Builders

1714 Seville Way
5.00(
21
)
•Approved Pro

Skytech Builders

1714 Seville Way
5.00(
21
)
•Approved Pro
Customers say: Quick response
Recommended by 100% of Angi customers
Recommended by 100% of HomeAdvisor customers
1132 local quotes requested

Welcome to Sky Tech builders, a general professional construction company. Our Decades of experience in the construction and home improvement Industry will help you achieve all your dreams and have the home you always wanted. At Sky Tech we are not just general contractors, we are also homeowners. We know what it’s like to have a big home improvement project in front of you. But we also know the satisfaction of the finished job, enjoying a new, updated home that you created. That’s why we are dedicated to making it as easy as possible for you to get exactly what you are seeking. As a construction company we want to help each and any of our customers accomplish their dreams of a complete home renovation. Our mission is to give you the best quality products and customer service making you and us enjoy this mutual adventure. We guarantee your satisfaction, and we won’t leave until the job is done right. We pride ourselves on the quality work we provide, while delivering great customer service! Check out our services offered and call or click to schedule an estimate today!

"The Hall and Master Bathrooms were fully renovated with new cabinets, countertops, showers and fixtures. Leo from Skytech assisted me along the way with option choices and recommendations. The crew was exceptional in their workmanship and were very detail oriented and made sure to clean the area prior to departure each day. I have received multiple compliments on the finished bathrooms. I would highly recommend Skytech Builders to anyone considering renovations and Leo in particular."

Bob H on July 2025

Welcome to Sky Tech builders, a general professional construction company. Our Decades of experience in the construction and home improvement Industry will help you achieve all your dreams and have the home you always wanted. At Sky Tech we are not just general contractors, we are also homeowners. We know what it’s like to have a big home improvement project in front of you. But we also know the satisfaction of the finished job, enjoying a new, updated home that you created. That’s why we are dedicated to making it as easy as possible for you to get exactly what you are seeking. As a construction company we want to help each and any of our customers accomplish their dreams of a complete home renovation. Our mission is to give you the best quality products and customer service making you and us enjoy this mutual adventure. We guarantee your satisfaction, and we won’t leave until the job is done right. We pride ourselves on the quality work we provide, while delivering great customer service! Check out our services offered and call or click to schedule an estimate today!

"The Hall and Master Bathrooms were fully renovated with new cabinets, countertops, showers and fixtures. Leo from Skytech assisted me along the way with option choices and recommendations. The crew was exceptional in their workmanship and were very detail oriented and made sure to clean the area prior to departure each day. I have received multiple compliments on the finished bathrooms. I would highly recommend Skytech Builders to anyone considering renovations and Leo in particular."

Bob H on July 2025

Avatar for Tech Line Construction Inc.

Tech Line Construction Inc.

6114 La Salle Avenue
New on HomeAdvisorNew on HomeAdvisor
•Approved Pro

Tech Line Construction Inc.

6114 La Salle Avenue
New on HomeAdvisorNew on HomeAdvisor
•Approved Pro
2206 local quotes requested
5 years of experience

Welcome to Tech Line Construction, your trusted partner in enhancing your home and transforming your wishes into visual and solid realities. With over a decade of unwavering dedication and a commitment to excellence, we have proudly served our clients in delivering top-tier construction solutions. We specialize in providing top-notch services for residential and commercial projects. Our commitment to professionalism, quality, and meticulous attention to detail sets us apart from our competitors. Choose Tech Line Construction for your next construction project and experience the highest level of service and craftsmanship. Bay Area General B Contractor Jose Rodriguez ( General Building contractor ) (510)798-5869 Office@techlineconstruction.info Tech Line Construction inc TechLineconstructiondesign.com CSLB # LIC 1094361 Commercial liability &Worker comp. Insured & bonded

Welcome to Tech Line Construction, your trusted partner in enhancing your home and transforming your wishes into visual and solid realities. With over a decade of unwavering dedication and a commitment to excellence, we have proudly served our clients in delivering top-tier construction solutions. We specialize in providing top-notch services for residential and commercial projects. Our commitment to professionalism, quality, and meticulous attention to detail sets us apart from our competitors. Choose Tech Line Construction for your next construction project and experience the highest level of service and craftsmanship. Bay Area General B Contractor Jose Rodriguez ( General Building contractor ) (510)798-5869 Office@techlineconstruction.info Tech Line Construction inc TechLineconstructiondesign.com CSLB # LIC 1094361 Commercial liability &Worker comp. Insured & bonded

...
Showing 1-10 of 977
FAQs for second story addition building service projects in Castro Valley, CA

For many homeowners, building up is worth the expense because it provides the extra bedrooms or living areas that can’t be accommodated within the existing footprint. A larger, updated home often commands a higher resale price, recouping a sizable share of the project cost while allowing you to stay in the neighborhood you love. Run the numbers with a real estate agent and contractor to ensure the expected return and day-to-day benefits align with your goals.

Whether it makes more sense to build up or out depends on your lot, budget, and local code. Building up preserves yard space and involves less foundation work, but you may need to vacate the home during construction. Building out avoids staircases and can proceed while you stay put; however, it encroaches on the yard and may face setback limits. Compare both options with your contractor before making a decision.

A structural engineer will first inspect the existing foundation for cracks, footings, and load capacity. Depending on the findings, the crew may pour new concrete footings, install steel or concrete piers, add reinforced beams, or tie additional rebar into the slab. These upgrades redistribute the weight of the new floor and bring the structure up to code. Your contractor will outline the specific reinforcement plan and timeline once the engineering report is complete.

The Castro Valley, CA homeowners’ guide to second story addition building services

From average costs to expert advice, get all the answers you need to get your job done.

See all articles
  • A renovated kitchen with a waterfall island

    HomeAdvisor’s DIY Kitchen Remodel Cost Guide looks at the cost of buying supplies and doing the work yourself. Find the key cost factors and how to cut expenses.

  • Secret room within bookcase

    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.