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Top Rated Contractor for Custom ADU in Gilroy, 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 Gilroy, California

Building a custom-built ADU in Gilroy, 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 Gilroy?

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


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

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


What zones are allowed to build an ADU in Gilroy?

R1, R2, R3, R4, RH.

What is the minimum ADU size in Gilroy?

The minimum ADU size in Gilroy is 150 square feet.

What is the maximum ADU and JADU size in Gilroy?

For Junior ADU or JADU, maximum size is 500 square feet. Meanwhile, for ADUs, it is 1,000 square.


How many ADUs are allowed on your property in Gilroy?

For properties with an existing or proposed single-family home, one ADU and one JADU are allowed.


For multi-family developed properties, two detached ADUs are allowed and up to 25% of the existing multi-family dwelling units or at least one unit may be converted from existing non-livable space.


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

  • 16' for a detached ADU proposed on a lot with a single-family home or one-story multi-family dwelling structure.

  • 18' for a detached ADU within ½-mile walking distance to a major transit stop or high-quality transit corridor on a lot with a single-family home or multi-family dwelling structure.

  • 18' for a detached ADU on a lot with an existing or proposed multi-story multi-family dwelling structure.

  • 24' for a detached ADU above a detached garage on a lot with a single-family home.

  • 25' for an ADU attached to an existing or proposed single-family home.


What are the required setbacks for ADUs in Gilroy?

  • ADUs may not encroach upon the required front yard area unless necessary to accommodate an 800 sq ft ADU.

  • 4 feet from the side and rear lot lines is required for a newly constructed ADU that is not replacing an existing structure.


What are the parking requirements for the newly constructed ADU in Gilroy?

One off-street parking space is required for newly constructed ADUs. However, exceptions to this requirement include being within one-half mile walking distance of public transit, located within an architecturally and historically significant historic district, situated within one block of a car share vehicle, residing on a street where on-street parking permits are mandated but not provided to the occupant of the ADU, or being built as part of a new home. Additionally, no additional parking space is required for a JADU or ADU on a multi-family developed property. 


Are there any other requirements when building an ADU in Gilroy?

New residential units, including ADUs, are required to complete a Nitrogen Deposition Only Application and pay a fee to the Santa Clara Valley Habitat Agency.


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

Yes. Owner occupancy of the property is required when there is a JADU. The owner must reside in the primary single-family residence, JADU or ADU on the property. For more information, check this Ordinance for Accessory Dwelling Units from the Gilroy City Code.  


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

Yes, ADU/JADU Affidavit is required.


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

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


What are the Departments/Agencies involved in the permit application process for ADU in Gilroy?

Planning, Building, Fire, and Engineering.


What are the fees for ADUs in Gilroy?

Building permit fee based on construction valuation, address fee, electrical, mechanical, and plumbing fees, technology fee, general plan fee, state fees including SMIP and BSARF, plan check fees, impact fees on units greater than 750sf, and school district fees on units greater than 500sf.


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 Gilroy?

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 Gilroy?

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 Gilroy?

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 Gilroy?

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 Gilroy?

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.

Fun Facts About Gilroy

Nestled in the heart of Santa Clara County, Gilroy, often known as the "Garlic Capital of the World," is a city that resonates with a unique blend of history, flavor, and community charisma. It's a place where the tang of garlic in the air signifies more than just a distinct aroma—it’s an integral part of its identity. For Gilroy locals and potential homebuyers, exploring this vibrant city reveals more than just its pungent fame. Here's a foray into fun facts and all there is to know about this intriguing locale.


Historical Insights That Shaped This Cultivated Community

Gilroy's origins date back to 1819 when Ygnacio Ortega, a soldier in the Spanish military, was given a land grant that encompassed what is now the city of Gilroy. Fast forward to the 1800s, and the arrival of Tennessean, John Gilroy, who married Ygnacio's daughter and established himself in the area, thus lending the city its name.

During the Civil War, the town became a bustling commercial center due to its strategic location near rail lines and San Francisco Bay. The development of agriculture—where fruits, vegetables, and grains initially took precedence—eventually gave way to what would become Gilroy's most recognizable crop, garlic, which was first planted there in the 1920s.

The significance of its agricultural roots echoes through time, shaping both the land and the people. Every pungent bulb was a testament to resilience, resourcefulness, and a taste that traveled across the globe.

Savoring Gilroy's Culinary Tapestry

When you're in Gilroy, every meal comes with a side of garlicky goodness. But the love for garlic is not just about flavor; it's a cultural phenomenon. The city hosts the famous Gilroy Garlic Festival, a gastronomic celebration that draws thousands from around the world. This homage to the layered cloves includes live entertainment, arts and crafts, and, of course, an array of culinary delights that span garlic ice cream to gourmet garlic-laced delicacies.


The festivity is not just a favorite among foodies; it is a testament to how a community has rallied around its agricultural heritage, transforming it into a signature culinary experience.

Notable Attractions Beyond the Fields of Garlic

While Gilroy wears its garlic badge with pride, it has more to offer beyond its delectable bulbs. One of the state's most cherished parks, Mount Madonna County Park, can be found in the city. Its serene setting provides breathtaking views of the valley and the Monterey Bay on clear days.

For those inclined toward history and culture, the historic Gilroy Museum and the San Benito House offer a glimpse into the past. The Gilroy Museum showcases the city's history through an array of exhibits, while the San Benito House, built in 1869, stands as a testament to the enduring architectural allure of bygone eras.

Not to mention, just a short drive away, you have the Pinnacles National Park, renowned for its unique geological formations and diverse habitats, attracting hikers, bird watchers, and lovers of the great outdoors.

Community Events That Bring Gilroy to Life

Year-round, Gilroy pulsates with community connections fostered through various events and festivals. The city's calendar is marked with events like the Downtown Live Summer Music Series, the Garlic City Car Show, and the colorful Dia de los Muertos Street Festival.

These festivities are more than mere occasions for revelry; they are threads that weave the diverse fabric of the community, bringing residents together in a colorful tapestry of shared experiences.

Real Estate Highlights: More Than Just a Market

Gilroy's real estate market is as varied as the recipes that feature garlic. With a mix of historic homes, family-friendly neighborhoods, and upscale residences, there’s something to suit every taste and preference.

One particular feature that stands out is the city's commitment to green space. Neighborhoods like Eagle Ridge and Glen Loma Ranch offer modern amenities mingled with a sense of openness, exemplified in the presence of parks, trails, and natural preserves.

The real estate scene is not just about brick and mortar; it’s a reflection of the community’s values, evolving in harmony with the city’s vision for the future.

There were 16 ADUs that received building permits in Gilroy in 2018 and 2019. 100% of those were intended to be made available to renter. 

There were around 59,032 people living in Gilroy. Average income is around $119,817 and average property value is at $784,550.

For those who call Gilroy home and those considering it, the city’s allure goes beyond the pungency of its beloved crop. It's in the stories of its founding fathers, the spirit of its festivals, the beauty of its parks, and the flavors that tantalize the palate.

Gilroy extends an open invitation to explore not just its streets but its rich history, vibrant present, and promising future. It beckons with a warm, garlicky breeze, carrying the promise of new friendships, shared experiences, and an unmistakable sense of belonging. Come, savor Gilroy—where the heart is as abundant as the harvest.

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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