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Top Rated Contractor for Custom ADU in Monte Sereno, 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 Monte Sereno, California

Building a custom-built ADU in Monte Sereno, 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 Monte Sereno?

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


What zones are allowed to build an ADU in Monte Sereno?

All single family (R-1-8, R-1-20, R-1-44) zones are allowed to build an ADU in Monte Sereno.


What is the minimum ADU size in Monte Sereno?

There is no minimum ADU size required in Monte Sereno.


What is the maximum ADU Size in Monte Sereno?

Maximum ADU size in Monte Sereno could be up to 1,000 or 1,200 square feet depending on the zoning district.


How many ADUs are allowed on your property in Monte Sereno?

  • For single-family dwelling, one (1) accessory dwelling unit, either attached or detached ADU, and one (1) junior accessory dwelling unit is allowed.

  • For multi-family dwelling, not more than two (2) detached accessory dwelling units are allowed. Additionally, the number of new accessory dwelling units authorized for conversion under this Subsection shall not exceed twenty-five percent (25%) of the existing dwelling units in the multi-family dwelling structure or one (1) new accessory dwelling unit, whichever is greater.


What is the maximum allowable height for ADUs in Monte Sereno?

The maximum allowable height for ADUs in Monte Sereno is 16 feet for one story. For an attached ADU in Monte Sereno, it can be the of same height as the main house, up to 30 feet.


What are the required setbacks for ADUs in Monte Sereno?

  • For a Detached ADU in Monte Sereno, it shall meet front yard setbacks (unless that would preclude an ADU), side and rear yard setbacks are 4 feet each, corner lot setback to meet the requirement of the zoning district.

  • For an Attached ADU in Monte Sereno, it shall meet the setbacks of the main house.


Are there any lot or location restrictions for ADUs in Monte Sereno?

Yes, an Attached accessory dwelling unit in Monte Sereno shall meet the setbacks of the main house. Moreover, an ADU of up to 800 square feet is allowed even if it will cause the lot to exceed the structural and impervious coverage limits.


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

One covered or uncovered parking is required unless the ADU is within 1/2 mile of transit or as part of a new house main house.


What are the Owner-Occupancy Rules for JADUs in Monte Sereno?

Owner must occupy either the JADU or the primary house.


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



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

Generally, ADUs and JADUs in Monte Sereno 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 Monte Sereno?

In addition to the City of Monte Sereno, plans are reviewed by Santa Clara County Fire Department and West Valley Sanitation District.


What are the specific rules for JADUs in Monte Sereno?

JADUs are not considered a separate unit for building code purposes.


What are the fees for ADUs in Monte Sereno?

City Council approved a 50% building permit and plan check fee discount for the first 225 property owners who provide a written intention to construct an ADU.


Are there any sample fees from recently builts projects for ADUs in Monte Sereno?

  • In 2002, a new 850 SF detached ADU had building permit fees of approximately $6,400.

  • In 2022, a new 1,200 SF detached ADU has building permit fees of approximately $11,500.


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 Monte Sereno?

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 Monte Sereno?

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 Monte Sereno?

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

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 Monte Sereno?

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 Monte Sereno, 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 Monte Sereno

Nestled snugly in Santa Clara County, Monte Sereno, California, stands as a quiet sanctuary just west of San Jose. This affluent enclave, known for its gracious living and wooded wanderings, offers much more than meets the eye. Are you a local looking to enrich your neighborhood knowledge? Or perhaps you're a potential homebuyer seeking a slice of scenic Californian splendor? Either way, get ready to uncover the charming essence of Monte Sereno through an exploration of its history, geography, community, and those little-known fun nuggets that impart the region's distinctive flavor.


A Tiny Enclave with a Towering Heritage

Monte Sereno's roots dig into the soil of early California with the arrival of Spanish explorers and missionaries. The region, once a part of the famed Rancho Rinconada de Los Gatos land grant, witnessed the growth of small-scale agriculture and vineyards, particularly prized for their auburn-hued Zinfandel grapes. The establishment of the Pueblo of San Jose by José Joaquín Moraga and the building of El Camino Real, the 'royal road' of Franciscan missions, set the stage for development and growth that would eventually lead to the founding of Monte Sereno in the 20th century.


A Gleaming Jewel in Silicon Valley's Crown

Location, they say, is everything, and this adage rings true for Monte Sereno. Positioned at the heart of Silicon Valley, it sits within the aura of innovation, just a stone's throw from tech giants and startup savants. The city’s close proximity to employment hubs and reputed educational institutions, including Stanford University, underscores its desirability for professionals and their families. Blending modern affluence with a hint of rustic charm, Monte Sereno cultivates an exclusive yet inclusive aura that draws kindred spirits.


Where Nature Crafts a Glorious Canvas

Monte Sereno wears its geographical blessings with quiet pride. Its picturesque setting at the foothills of the Santa Cruz Mountains treats residents to stunning vistas and an idyllic microclimate where sunny days are the norm. The Los Gatos Creek courses through the city, refreshing it with the spirit of flowing waters, while its lush parks and open spaces beckon to nature lovers and picnickers alike. The neighborhood's topography offers a mix of landscapes, from shady oak groves to sunlit meadows, making each foray outdoors a unique adventure.


Down-to-Earth Elegance and Upmarket Affluence

In Monte Sereno, community is not just a concept — it's a way of life. The city's socio-demographic fabric weaves a tale of unity among diversity, with residents sharing a deep appreciation for a quality life. The town's social calendar is dotted with events that celebrate good times and goodwill. From local farmers' markets to cultural festivities, the community ethos thrives, fostering a neighborly spirit that is as warm and welcoming as the California sun.


The Coveted Corners of the Residential Chessboard

Real estate in Monte Sereno is the personification of exclusivity. With a mix of architectural styles ranging from historic Victorian to contemporary chic, the city presents options that cater to a myriad of tastes. The residential landscape is dominated by sprawling estates, interspersed with manicured gardens and opulent pools, defining opulence in suburban living. The housing market here is known for its steady resilience and is highly coveted among those seeking quintessential Californian living.


A Tapestry Woven with Local Legends

For a town with fewer than 4,000 residents, Monte Sereno boasts more than its fair share of local lore. Did you know that the city's Saratoga-Los Gatos Road is rumored to be the same route used by Oregón y California Trail emigrants in the 1840s and 1850s? Or that it's home to one of the oldest parks in California, the enchanting Vasona Lake County Park? Hidden gems such as the iconic "Grandmother Tree" — an ancient redwood whose age is estimated at over 1,800 years — add a mythical quality to Monte Sereno, elevating it to a status beyond suburban sanctuary.


Echoes of the Past, Beacons for the Future

Each summer, the city's boulevards come alive with the Monte Sereno Art and Wine Festival, a vibrant celebration of creativity and community. The occasion not only offers a sensory feast in the form of local art and delectable wines but also underscores the city's commitment to preserving its heritage while looking ahead to a future bright with possibilities. Monte Sereno gradually crafts an identity that mingles the cultural effervescence of local artists with the economic legacy of Silicon Valley innovators.

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

To live or even visit Monte Sereno is to glimpse a world that is both timeless and trendsetting. Here, the bygone intertwines with the bustling present, each layer adding depth to the allure of this Californian gem. Whether you're interested in the region's historical narratives, its topographical riddles, or its future promises, Monte Sereno beckons as a locale where life's tapestry is woven with pride and purpose, delighting all who venture within its bounds.

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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