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Top Rated Contractor for Custom ADU in Milpitas, 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 - from project managers, architects, builders, to contractors -  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 Milpitas, California

Building a custom-built ADU in Milpitas, 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 Milpitas?

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


What zones are allowed to build an ADU in Milpitas?

All Residential Districts (R1-R5) and Mixed Use Districts (MXD, MXD2, MXD3) Zones are allowed to build ADUs in Milpitas.

What is the minimum ADU size in Milpitas?

The minimum ADU size in Milpitas is 150 square feet.

What is the maximum ADU Size in Milpitas?

  • Attached ADU or Detached ADU: 850 sq ft for a studio or one bedroom and 1000 sq.ft. for a two bedroom unit.

  • Attached or Detached ADU in the "H" Hillside Combining District: 1200 sq.ft Attached ADU created on a lot with an existing primary dwelling is limited to 50% of the floor area of the existing dwelling.


What is the maximum allowable height for ADUs in Milpitas?

  • A detached ADU in Milpitas created on a lot with an existing or proposed single-family or multi-family dwelling unit shall not exceed 16 feet in height.

  • A detached ADU in Milpitas may be up to 18 feet in height when located on a lot with an existing or proposed single-family or multifamily unit that is located within one-half mile walking distance of a major transit stop or a high quality transit corridor.

  • A detached ADU in Milpitas may be up to two additional feet in height (for a maximum of 20 feet) if needed to accommodate a roof pitch on the ADU that is aligned with the roof pitch of the primary dwelling unit.

  • A detached ADU in Milpitas created on a lot with an existing or proposed multi-family dwelling that has more than one story above grade shall not exceed 18 feet in height.

  • An attached ADU in Milpitas cannot exceed 25 feet in height or the height limitation imposed by the standards for the underlying zoning district, whichever is less.


What are the required setbacks for ADUs in Milpitas?

The required setbacks for ADUs in Milpitas are 25 feet minimum for the front yard and 4 feet each for rear and side. However,  no setback is required if the ADU is constructed in the same location and to the same dimensions of an existing structure.

What are some lot or location restrictions for ADUs in Milpitas?

  1. No ADU in Milpitas may cause the total lot coverage of the lot to exceed 50%.

  2. Detached accessory dwelling units in Milpitas must be built at least 5 feet from the rear wall of the primary dwelling unit.

  3. No ADU in Milpitas may cause the total percentage of open space of the lot to be less than 50%.


What are the parking requirements for one off street for ADU in Milpitas?

  • The ADU is located within one half (½) mile walking distance of public transit.

  • The ADU is located within an architecturally and historically significant historic district.

  • The ADU is part of an existing primary residence or an accessory structure.

  • On street parking permits are required but not offered to the occupant of the ADU.

  • An established car share vehicle stop is located within one block of the ADU.

  • When then permit application to create an ADU is submitted with an application to create a new single-family or new multi-family dwelling on the same lot, provided that the ADU or the lot satisfies all other requirements for new development.


What are the Landscape Design Standards for ADUs in Milpitas?

Evergreen Landscape screening must be planted and maintained between the ADU and adjacent parcels.

  • At least one 15 gallon size plant must be planted for every 5 linear feet of exterior wall, or alternatively, at least one 24 inch box size plant must be planted for every 10 linear feet of exterior wall.

  • These plants must be at least 6 feet tall when installed, or as an alternative a solid fence of at least 6 feet may be installed.

  • All landscaping shall be drought tolerant.


What are the Architectural Design Standards for ADUs in Milpitas?

  • Materials and colors of the exterior walls, roof, and windows must match the appearance of the existing or proposed primary dwelling.

  • The roof slope must match that of the dominant roof slope of the primary dwelling.

  • An ADU or JADU in Milpitas must have an independent exterior entrance, separate from that of the primary dwelling. The entrance to an attached ADU or JADU must be located on a side or rear building facade, not facing the public right-of- way.

  • Exterior lighting is limited to down lights.

  • The interior horizontal dimensions of the ADU must be at least 10 feet wide in every direction, with a minimum interior wall height of 7 feet.

  • Windows and doors may not have a direct line of sight to a neighboring residential property, and fencing, landscaping, or privacy glass can be used to provide screening and prevent a direct line of sight.

  • Windows located on the second story of an ADU or JADU must be either clerestory with the bottom of the glass at least 6 feet above the finished floor, or use frosted or obscure glass to preserve privacy.

  • The ADU and primary dwelling must use the same driveway to access the street.


What are the Owner-Occupancy Rules for ADUs in Milpitas?

  • An ADU permitted between 1/1/2020 and 1/1/2025 is not subject to any owner-occupancy requirement.

  • Unless State law requires differently, all ADUs permitted on or after 1/1/2025 will be subject to an owner occupancy requirement.

  • JADUs shall be subject to an owner-occupancy requirement, where the property owner must live in either the primary house or the JADU.

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

Yes. Deed Restriction must be recorded requiring compliance with any owner-occupancy regulations.


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

ADUs and JADUs can not be rented for less than 30 days at a time. With the building permit application, the applicant must provide the city with an estimate of the projected annualized rent that will be charged for the ADU or JADU.

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

  • Planning Department

  • Building Department

  • Land Development Department


What are the specific rules for JADUs in Milpitas?

JADUs in Milpitas must be constructed within the walls of the existing or proposed building. It can be up to 500 sq ft. It must include an efficiency kitchen (a cooking facility with appliances, and a food preparation counter with a total area of at least 15 sq ft. and food storage cabinets with a total of at least 30 sq ft of shelf space) and must have a separate sanitation facilities or share sanitation facilities with the existing or proposed primary dwelling.


What are the specific rules for the owner occupancy in Milpitas?

All JADUs in Milpitas are subject to an owner occupancy requirement. The owner-occupancy requirement does not apply if the property is entirely owned by another governmental agency, land trust, or housing organization.

What are the fees for ADUs in Milpitas?

  • Building Safety Fee (Plan Review, Inspection, Miscellaneous)

  • Planning Fee (Plan Review)

  • Land Development Fee (Plan Review)

  • Utility Connection Fee (Water, Sewer/Treatment Fee)

  • New Address Request

  • No impact fees are required for an ADU or JADU that is less than 750 sq ft.

  • Any impact fee that is required for an ADU that is 750 sq ft or larger is assessed based on the floor area of the primary house.

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 Milpitas?

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 Milpitas?

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 Milpitas?

You can do a Google Search for the keyword “adu contractor near me” or get referrals from your friends or local community in Milpitas CA. 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 Milpitas?

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 Milpitas?

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 projects in Milpitas, 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,

  • separate 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 Milpitas

Nestled in the Santa Clara Valley and situated conveniently between the bustling technology centers of San Jose and Fremont, Milpitas silently boasts its significance in the Bay Area. The city's name derives from the Mexican land grant of Rancho Milpitas, which gave rise to an area that has long been a pivotal point of the region's historical and economic undertakings. But beyond this historical context, Milpitas holds a wealth of facts and stories waiting to be explored.


Historical Insights

The Unexpected Founding

In the early 1800s, the mission system was in full swing, and the area that would become Milpitas served as a rest stop for Spanish soldiers and missionaries. It was this functional foundation that saw the city's inception, quite unexpectedly, when Californian land grant owners constructed homes and buildings, and the city began to form.


Gold Rush Connections

The boom of the Gold Rush brought a wave of population growth to California, and Milpitas was no exception. Here, the gold brought not only fortune-seekers but also a new wave of settlers that contributed to the city's development, turning it into a vibrant hub with a growing community spirit.


The Milpitas Historical Society

Preserving the city's past, the Milpitas Historical Society has played a critical role in maintaining and showcasing the formidable history of the area. With its headquarters in the Milpitas Public Library, the society regularly hosts history-focused events and has an impressive collection of artifacts and records that tell the story of old Milpitas.


Cultural Richness

The Heart of Diversity

With a multiethnic population, Milpitas represents an inspiring tapestry of various cultures. This diversity is celebrated through cultural events and festivals that reflect the city's proud multicultural heritage. From Diwali to Lunar New Year, the city is lit up with celebrations that mirror the vibrant mosaic of people who call this place home.


The Milpitas International Festival

An annual event that attracts visitors from across the Bay Area, the Milpitas International Festival is a high-energy celebration of diversity. The festival features a parade showcasing different cultures, live music, dances, and an array of international cuisine, encapsulating the global village spirit right in the city's heart.


Geographical Marvels

The Heart of the Bay

Milpitas sits in the middle of the Bay Area, offering easy access to a myriad of locations and attractions, from the Silicon Valley's tech havens, the picturesque landscapes of the Santa Cruz Mountains, to the cultural magnets of San Francisco. Its central location means that no adventure is too far, and the city acts as a home base for those seeking the varied experiences the region offers.


Mild Climate All Year Round

Not too hot, not too cold — Milpitas enjoys a comfortable Mediterranean climate that's ideal for those not keen on extremes. The city basks in sunshine most of the year, with moderate temperatures providing perfect conditions for outdoor activities and exploration.


Landmarks of Milpitas

Milpitas is home to several landmarks that are must-sees for both tourists and residents. The great mall, once the largest in Northern California, and Ed Levin County Park, offering a panoramic view of the valley, are just a couple of examples that are perfect for leisurely weekends or casual strolls after work.


The Economy

From Ranchland to the Tech Boom

Originally ranchland, agriculture dominated Milpitas' economy well into the 20th century. However, the city was quick to adapt during the tech boom and is now a pivotal player in the semiconductor industry. Companies like KLA-Tencor and a host of established and startup tech firms call Milpitas home, providing ample career opportunities for the local workforce.


A Shopping Haven

The Great Mall of the Bay Area, a prominent feature of Milpitas, is Northern California's largest enclosed outlet shopping center. Boasting a plethora of stores, restaurants, and entertainment options, the mall serves as a retail and recreational haven, drawing in shoppers from all over the region.


Post-Industrial Revitalization

The city's industrial past has seen it evolve into a diverse economic landscape. The redevelopment of former industrial sites has given rise to business parks, a testament to the city's adaptability and commitment to maintaining a robust economy for both local residents and the greater Bay Area community.


Delving into the Fun

World's Largest Odor-Removal Plant

Arguably one of the most unique features of Milpitas is its wastewater treatment plant, notorious for the occasional funky scent that wafts through the air. Yet, what many might not realize is that this is also the largest advanced odor-control treatment plant in the world, showcasing cutting-edge environmental engineering right in our backyard.


The Red Hot Chili Peppers Connection

The Grammy Award-winning band, the Red Hot Chili Peppers, gained inspiration for their 1991 album "Blood Sugar Sex Magik" while residing in a rented house in the Milpitas foothills. The secluded location proved to be the creative retreat that crafted one of the band's most celebrated works, setting the stage for musical milestones beyond the city limits.


The Craze Over Calaveras Reservoir

Tucked away in the hills east of Milpitas is the serene Calaveras Reservoir. The reservoir's famous Sunol water temple, engineering marvel, and connections to the Hetch Hetchy water system attract visitors who come to admire the oasis amidst the wilderness.

There were 47 ADUs that received building permits in Milpitas in 2018 and 2019. All of these were intended to be made available to renter. There were about 84,196 people living in Milpitas. The average income is $137,981 while the average property value in Milpitas is at $980,851.

Milpitas's blend of history, culture, and quirk makes it an irresistible destination for those in search of a rich community experience. With its strategic geographical location, economic dynamism, and surprising facts waiting to be unraveled, there's always something new to discover in this dynamic city. For residents and visitors alike, Milpitas proves time and again that its unique blend of old-world charm and innovative spirit is truly something to be celebrated.

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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