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Top Rated Contractor for Custom ADU in Campbell, California

Featured Project

Located in Pleasanton, this detached accessory dwelling unit measures up to 440 square feet. It has a kitchen, bathroom, bedroom, living room, walk-in closet, and a utility room. 

With proper design, it’s amazing how we’re able fit all these amenities in this secondary dwelling unit. We have to say that it’s even more fulfilling to have a custom-built ADU with personalized designs and layouts that fit your lifestyle needs. One interesting thing about this ADU is the addition of a patio just outside the ADU since Christina loves to cook and gather with friends.

Watch this video to take a look inside this beautiful custom-built ADU:


Cristina has been living with her mother for a year and a half. After some time, she realized she wanted to have her own space so they talked about building an Accessory Dwelling Unit (ADU).

The thought of building a custom-built ADU in Pleasanton was a win-win solution because she can finally have a space of her own and, in the future, she could rent it out to tenants, giving her additional source of passive income.


What this video as Christina shares with you her experience in building her own detached ADU from start to finish.

About ADU Builders Group

At ADU Builders Group, we are on a mission to revolutionize how homeowners in the Bay Area expand their living spaces. Our core dedication lies in helping these homeowners effortlessly build their Accessory Dwelling Units (ADUs) by streamlining every step of the process. With the rising need for additional living space, our company offers a timely solution that not only increases property value but also supports multi-generational living and generates potential rental income.


Our Expertise

We specialize in creating customized livable spaces tailored to fit the needs of every homeowner. Our product range includes:

Accessory Dwelling Units (ADUs)

Independent living units equipped with their own sleeping, cooking, and bathroom facilities.

Attached ADUs

These units share a wall with the main home, perfect for those looking to maintain close proximity to their additional living space.

Detached ADUs

Stand-alone units that offer privacy from the main home, ideal for renters or as guesthouses.

Junior ADUs (JADUs)

Smaller living units converted from existing spaces within the main home, such as bedrooms or garages, offering a compact but fully functional living solution.


Why Choose Us?

Our commitment to excellence and customer satisfaction is reflected in our unique selling points:


3 Years Service Warranty with Complimentary Annual Inspection

We stand behind the quality of our work with a 3-year service warranty on all our custom-built ADUs, ensuring peace of mind for our clients. To further assure the durability and maintenance of your investment, we provide a complimentary annual inspection, making sure your ADU remains in peak condition. This service warranty is on-top of 10-year standard warranty on structural components.


Streamlined Process

Understanding the complexity involved in building a custom-built ADU, we've refined our processes to offer an effortless experience. From initial design consultation to final walkthrough, our team of experts is with you at every step, ensuring a seamless transition from vision to reality.


Customizable Solutions

Recognizing that every homeowner's needs are unique, we offer fully customizable ADU solutions. Whether you're looking for a cozy JADU for family or a spacious detached ADU for rental income, we adapt our designs to meet your specific requirements.

Our Commitment:


At ADU Builders Group, we’re more than just home builders building custom ADUs. We’re about creating valuable, functional spaces that enhance lifestyles and bring visions to life. With a keen focus on innovation, quality, and customer satisfaction, we are dedicated to transforming the way the Bay Area thinks about home expansion.


Contact us today by filling out the form below to take the first step towards building your own custom-built ADU.

How to Build an ADU in Campbell, California

Building a custom-built ADU in Campbell, California can be summarized into a seven-step process:

  1. Get Started

  2. Learn The Rules

  3. Set your Budget

  4. Design your ADU

  5. Apply for Permits

  6. Build your ADU

  7. Rent it Out or Move It

How to get started with ADU?

You can start with your ADU by thinking about what you want and asking yourself these questions:

  • Who am I building this for?

  • What are the amenities I need to add into this project to support my family members, my tenant, or my own needs?

  • How can it improve and support my lifestyle?

If you’re looking for an inspiration, you can go check your local neighborhood for anyone who owns a casita, visit online community groups for ADU on Facebook and other social media channels, check these floorplans compiled by Santa Clara County ADU, search for “ADU contractor near me” and check portfolios of local ADU builders in your area, or simply consult with us at ADU Builders Group by filling out the form below.


What are the Standards and Rules for Building an ADU in Campbell?

Here’s a compilation of answer to frequently asked questions about the standards and rules for building in ADU in Campbell.


What zones are allowed to build an ADU in Campbell?

  • All residential zoning districts, and

  • P-D (Planned Development) Zoning District on a parcel with a General Plan land use designation that directly corresponds to a residential zoning or mixed-use district (as specified by Section 21.04.020).


What is the minimum ADU size in Campbell?

150 square feet.

What is the maximum ADU Size in Campbell?

1,200 square feet.

What is the maximum JADU Size in Campbell?

500 square feet.


Is there any restriction for the maximum allowable size of ADUs and JADUs in Campbell?

Yes. Attached or interior ADUs (and JADUs) shall not exceed 50% of the living area of the primary dwelling unit.

How many ADUs are allowed in a Single-Family Property in Campbell?

One ADU and one JADU may be built, as long as the property satisfies the minimum standards outlined in Section 21.23.020 of the Campbell Municipal Code.

How many ADUs are allowed in a Multi-Family Property in Campbell?

Up to one ADU for every four non-ADU units within the dwelling structure can be created from existing, non-livable space. In addition, up to two detached ADUs may be built.


How many kitchens and living rooms can an ADU in Campbell contain?

An ADU in Campbell can contain only one kitchen and one living room (defined as a habitable room with an area not less than one hundred twenty square feet).

What is the maximum allowable height for detached ADU in Campbell?

  • Detached ADUs may be up to 2 stories if the (existing or proposed) primary dwelling unit is also 2 stories.

  • Detached ADUs may be up to 18’, with an additional 2' height permitted if necessary to align the roof pitch with the roof pitch of the (existing or proposed) primary dwelling unit.

  • After 18’, the height of a detached ADU may not exceed the height of the primary dwelling unit.

What is the maximum allowable height for an attached ADU in Campbell?

Attached ADUs in Campbell may not exceed the height specified by the applicable zoning district and/or neighborhood Plan.

What are the required setbacks for ADUs in Campbell?

  • Setback requirements are determined by the zoning.

  • Statewide exemption accessory dwelling units are exempt from the otherwise required (1) front setback, (2) building separation, (2) floor area ratio, (3) lot coverage, (4) open space, and (5) design requirements specified by Section 21.23.030 (Accessory dwelling unit development standards) and the design and placement requirements specified by Section 21.23.060 (Special provisions for historic properties), except that the exemption to the front setback for an attached accessory dwelling unit shall only apply to that portion of the primary dwelling unit occupied by the accessory dwelling unit. All other standards, requirements, and restrictions of this Chapter shall continue to apply.


Are there any lot or location restrictions for ADUs in Campbell?

Yes. An ADU may be located in front of, to the side of, or behind the primary dwelling unit. Lot coverage and floor area ratio (FAR) must comply with the zoning district. As for the open space requirements, creation of an ADU can not reduce the required open space to less than what is specified by zoning. Check with staff for possible exemptions.

What are the parking requirements when building an attached or detached ADU in Campbell?

ADU parking requirements default to State Law. Attached and detached ADUs do not require additional parking if they are within 1/2-mile walking distance to transit (including a ferry), in an architecturally or historically significant district, one block from car-share access, located in an area where on-street parking permits are required but not provided to the occupant, or built as a part of new a home.

What are the parking requirements when building an ADU or JADU in Campbell?

There are no parking spaces required for new ADUs or JADUs. Parking spaces that are removed to allow for an ADU or JADU do not have to be replaced (e.g., by demolition or conversion of a garage).

What are other notable design guidelines when building an ADU in Campbell?

  • Balconies, second-story decks, and rooftop terraces are prohibited.

  • All second-story windows less than eight feet from rear and interior-side property lines must be clerestory with the bottom of the glass at least six feet above the finished floor.

  • Historically designated properties may only have interior ADUs and detached ADUs limited to one-story, 16-feet in height, located behind the primary home, and designed to match the primary home.


Is there any Owner-Occupancy Rule for JADU in Campbell?

Yes. On a property with a Junior ADU, the property owner must live in either the Junior ADU or the primary dwelling unit. The community development director may require a deed restriction documenting this owner-occupancy rule before issuing a building permit.


Are there any deed restrictions when building accessory dwelling units in Campbell?

Yes. Recording of deed restriction is required before a building permit can be issued. Individual HOA requirements as applicable.

What is the regulation for renting accessory dwelling units or JADU in Campbell?

Generally, ADUs and JADUs cannot be rented for fewer than 30 days at a time.

What Departments/Agencies are Involved in the Permit Application Process in Campbell?

  • Campbell Community Development Department- Planning, Building, Public Works

  • Santa Clara County Fire District

  • West Valley Sanitation District

  • Santa Clara County Recorder's Office

  • Campbell Union School District (if ADU is above 750 sq ft)


What are the fees for ADUs in Campbell?

Fees vary depending on the size of the ADU, and typically range from $2,500 for a simple garage conversion to $14,000 for construction of a 1,200 detached ADU.ADUs less than 750 square feet are not required to pay the Campbell Union School District fee and Park fee.

You may refer to Local Rules & Contacts - Santa Clara ADU , then select your city to check for the latest rules in your area. Check with your local city as well to assess your property and ascertain its suitability for an ADU. Determine the type of ADU you can build based on your local zoning laws and the physical characteristics of your property.

How much does it cost to build an ADU in Campbell?

For custom ADUs, the estimated cost per square foot can range from $450 - $500. You can start planning your budget using this estimate. You may also contact us for a more detailed quotation by filling out the form below. 


You may also be interested to look into financing options.

How to finance an ADU in Campbell?

To finance your ADU, you have several options from loans, HELOC, to grants.



Several loan options exist for financing an ADU project. A home equity loan, for instance, allows you to borrow against the equity you've built up in your home. Another alternative is a construction loan, which is a short-term loan that covers the cost of construction. Once the construction is complete, the loan can either be paid off or converted into a standard mortgage.


Home Equity Line of Credit (HELOC)

Similar to a home equity loan, a HELOC also lets you borrow against your home's equity. However, it works more like a credit card, where you have a line of credit you can draw against as needed.



In certain situations, grants may be available for ADU construction. Some local and state programs offer grants, especially targeted at homeowners looking to build ADUs for low-income renters or seniors. It's worth researching local initiatives and programs in your area. The CalHFA 40k ADU Grant is one notable grant to look into.


Do you have financing options?

Yes, we partner with reputable finance companies to help our clients build their ADU as soon as possible.

How to Design your ADU?

You can start by getting some inspiration then hiring a professional architect to lay out your vision for you. It would even be better to look for a reputable local ADU contractor in your area that offers both design and build services.


Discuss your initial design with the local Planning staff. After revisions, finalize your design and have your contractor prepare the plans for permitting.


How to find the right local adu contractor near me in Campbell?

You can do a Google Search for the keyword “adu contractor near me” or get referrals from your friends or local community. Then go on checking their credentials, licenses, and insurance. Review their portfolios and ask for references. Get multiple quotes and compare. Prioritize clear communication and trust your instincts.


Do You Need a Permit for an ADU in Campbell?

Yes. Start by confirming application requirements with your local staff. Then, submit your application online or in-person and pay any required fees. Staff will review your application within 60 days, and often sooner. Revise your application if needed. Staff will tell you the best way to be in contact, likely via email. Generally, outstanding fees are due before your permit is issued.  


How to Build your ADU in Campbell?

The best way to do it is by working with a reputable contractor like ADU Builders Group. We’ll handle everything you need for your ADU from design to moving in. We believe that in every successful project, the key is effective communication. That’s why, we’ll regularly update you with the progress of your project for your peace of mind.


Rent it Out or Move In 

After passing the final inspection, it’s ready for move-in! A bit of landscaping would be advisable if you prefer to beautify and add more personality to your property. Enjoy your new ADU! 



Check out this overview of the entire ADU process prepared by the Santa Clara County ADU.

What is an Accessory Dwelling Unit?

ADUs are self-contained secondary living units that share the same lot as a primary residence. They can be either attached or detached from the primary residence and are often smaller in size. An ADU typically has its own entrance, kitchen, bathroom, and living space. It can come in different forms such as a basement apartment, converted garage or attic space, or a separate building on the property.

ADU is also sometimes referred to as one of the following depending on their uses or for whom it is built:

  • granny flats,

  • in-law suites,

  • backyard cottages,

  • secondary suite,

  • secondary dwelling unit, or

  • casita.

Whatever people choose to call it, the primary purpose of ADUs,both prefab and custom-built, is to provide additional housing options for homeowners. They can be used for various purposes such a

  • accommodating aging parents,

  • independent living space for adult children, or

  • source of rental income.




Rising Demand of ADUs in California

California, known for innovation and opportunity, attracts dreamers and visionaries from all over the world. However, behind its successful appearance, there is a growing housing crisis that has been getting worse for years.


Despite its technological advancements, cultural diversity, and economic prowess, the state faces shortage of affordable housing. Factors contributing to this housing shortage are population growth, limited construction, strict zoning rules, and high real estate prices. This makes it difficult for average earners to find affordable homes. In the face of this crisis, ADUs have emerged as a promising solution.


From 3,163 ADUs built in 2018, this number has risen to 13,439 in 2022, indicating a 325% increase in the number of ADUs built. These data are based on a report from UC Berkeley’s Center for Community Innovation. Since then, the concept of accessory dwelling units (ADUs) has been continuously gaining popularity in the housing market.



What are the Benefits of having an ADU on your Property?

Having an ADU on your property can offer several benefits to you such as providing an opportunity to earn extra income by offering it as a rental property or allowing you to keep your families closer together while still having a sense of privacy and independence. Custom-built ADU offers a convenient housing option for aging parents, adult children, or guests.


Moreover, adding an ADU can potentially increase the overall value of your property.


ADUs can help address housing shortages as well by providing more affordable housing options in high-demand urban areas. They offer a smaller, more affordable alternative to traditional single-family homes. For individuals or families who cannot afford a traditional single-family home, ADUs are considered as a more affordable housing option.


ADUs can serve various purposes, including a rental unit, home office, guesthouse, or even a space for aging in place. The flexibility allows homeowners to adapt the space to their changing needs over time. That’s how you can benefit from building an ADU on your property.


What are Different Types of ADU?

When it comes to accessory dwelling units (ADUs), there are several different types that cater to diverse needs and property structures. Let's discuss the four types of ADUs mentioned in the ADU Handbook published by the California Department of Housing & Community Development.


Attached ADUs

Attached ADUs are an extension or addition to the primary residence. They are physically attached to the main building and might involve converting a garage or adding a new structure onto the existing house. This type of ADU is beneficial for those homeowners who want to maintain a direct connection between the main house and the ADU.


​Detached ADUs

Detached ADUs, on the other hand, are separate structures that are independent of the primary residence. These are often constructed in the backyard and can offer a greater degree of privacy compared to attached ADUs. Detached ADUs are a great option if your lot has ample outdoor space.


Converted Existing Space ADUs

Converted Existing Space ADUs involve transforming an already existing part of the home into a self-contained living space. This could mean converting a basement, attic, or even a section of the house into an ADU. This type of ADU is a cost-effective choice as it utilizes existing structures.


Junior ADUs

Junior ADUs (JADUs) are smaller in size, typically up to 500 square feet, and are located within the walls of the primary dwelling. They include their own separate entrance, as well as an efficiency kitchen. JADUs offer a more compact, yet self-sufficient, living arrangement.


Each type of ADU has its unique set of advantages and considerations. It's essential to assess your specific needs, local regulations, and the available space on your property before deciding on the most suitable type of ADU. Whether it be an attached ADU for easy accessibility, a detached ADU for added privacy, a converted existing space ADU for an economical solution, or a junior ADU for a smaller-scale dwelling option, you can find a variation that fits your needs.

Pros of Living in Campbell

27 ADUS in Campbell received building permits in 2018 and 2019. None of these were intended to be made available to renter. 

Nestled in the heart of Santa Clara County, Campbell is more than just a city—it's a lifestyle. With a population that cherishes its small-town feel, Campbell manages to be both an earmark of historic California and a beacon of modern living. Here, we'll uncover the layers that make Campbell a coveted destination for both first-time home seekers and seasoned locals alike.


Cost of Living

Living Large Without the High Price Tag

Campbell has quietly garnered recognition as an affordable enclave within the often exorbitant Silicon Valley. Unlike its pricier neighbors, Campbell offers a more approachable cost of living, ensuring that residents can enjoy the various amenities without breaking the bank. Home to a mix of housing styles that range from cozy bungalows to stately modern homes, Campbell promises diversity of choice while maintaining a moderate price point.


Community and Amenities

A Haven for All Ages

Families in Campbell can attest to the richness of community life that's on offer here. The city boasts a strong network of schools, both public and private, that are renowned for their quality education. The local parks provide ample green spaces for recreation, while farmer's markets, artisan fairs, and community events ensure that there is always something happening to engage the residents.


Shopping and Dining Experiences Unmatched

Campbell's downtown is a bustling hub of activity, replete with boutique shops, sumptuous restaurants serving cuisine from around the world, and delightful cafes that beckon locals for a leisurely cup of coffee. Shopping enthusiasts can find an array of retail options, from one-of-a-kind specialty stores to larger chains, offering everything one might need within the city limits.


Location and Accessibility

Prime Position in the Valley

Campbell's strategic location within Silicon Valley affords residents the convenience of quick access to the region's major tech centers and employment opportunities. The city's proximity to Highway 17 and 85, coupled with excellent public transportation options, makes navigating the Bay Area a breeze.


Quality of Life

Safety and Well-being at the Forefront

One of the most significant draws of Campbell is its reputation for safety and community policing. Local law enforcement and active neighborhood watch programs contribute to a feeling of security that is priceless for its residents. Hospi​​tality is also prominent in Campbell with healthcare services that match the city's tranquil vibe, ensuring top-notch medical facilities are within reach.

Recreation and Culture Abound

For those looking to unwind and enjoy life outside the fast lane, Campbell delivers with a plethora of cultural and recreational activities. Whether it's an evening of theater at the historic Campbell Heritage Theatre, a leisurely stroll through the nearby Creek Trail, or a day of family fun at the nearby Pruneyard Shopping Center, Campbell provides a diverse range of options to cater to various interests.


Real Estate Market

Homes that Harmonize with Your Lifestyle

The real estate market in Campbell is dynamic, offering homes that cater to a spectrum of lifestyles. From first-time homebuyers seeking a cozy starter home to seasoned investors looking for opportunities in the market, there is something for everyone. Home appreciation rates in Campbell are steady, making it not just a great place to live but also a wise investment choice.

Trends and Investment Insight

Prevalent real estate trends in Campbell indicate a sustained market growth, driven by the city's allure and its position in Silicon Valley. For investors, the stability and potential for future appreciation make Campbell a prime location to consider. The diversity of residential options, coupled with the city's progressive development initiatives, ensures that the housing market remains robust and varied.

Campbell is much more than a city in Silicon Valley—it's a community brimming with opportunities for an enriching livelihood. The seamless blend of quality living, affordability, and California charm makes Campbell an ideal choice for anyone looking to take root in a place that offers both the tranquility of suburban living and the vigor of urban excitement. Whether you're in search of a new home that resonates with your lifestyle or simply exploring the bounty that the Bay Area offers, Campbell eagerly awaits with its open arms and endless possibilities.​

Consult with Us.

Got inquiries? Wanna start building your own ADU?

Reach us out by submitting the form below.

Service Areas

  • ADU Palo Alto

  • ADU San Jose

  • ADU Santa Clara

  • ADU Saratoga

  • ADU Sunnyvale

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