ADU Builder Berkeley
Custom, High-Quality Accessory Dwelling Units
Are you looking to build an Accessory Dwelling Unit (ADU) in Berkeley, CA?
Keep Your Family Close with a Custom ADU
Whether you want to create a comfortable space for aging parents, independent living for adult children, or a guest house for extended family, ADU Builders Group is your trusted ADU builder in Berkeley, California.
With over 20 years of experience, we specialize in designing and constructing high-quality, custom-built ADUs that strengthen family bonds, enhance multigenerational living, and improve your lifestyle while ensuring compliance with local building regulations.
Build with Peace of Mind
We are the only ADU company in Berkeley that offers a three (3) years project warranty on our services with complementary annual project inspection. All of this on top of the ten (10) years warranty on structural components.
✔ 3 Years Project Warranty
✔ Complimentary Annual Inspection
✔ 10 Years Structural Warranty
Why Choose Us?
1. Peace of Mind with Industry-Leading Warranties
✅ 3 Years Project Warranty – We stand by our craftsmanship, ensuring any issues within the first three years are addressed promptly and professionally.
✅ Free Annual Inspection – Our commitment to quality extends beyond project completion, we provide a free annual inspection, for the first three years after project completion, to ensure your ADU remains in excellent condition.
✅ 10 Years Structural Warranty – Our ADUs are built to last, and we back them with a decade-long structural warranty, giving you confidence in the longevity of your investment.
2. Expert Guidance & Hassle-Free Process
✅ Permitting & Compliance Experts – Navigating Sunnyvale's ADU regulations can be complex, but our experienced team ensures a smooth approval process, handling all paperwork and city requirements to prevent costly delays.
✅ 20+ Years of Construction Expertise – With decades of expertise in the construction industry and a dedicated focus on ADUs for over five years, we bring the knowledge, efficiency, and craftsmanship necessary to deliver high-quality results every time.
✅ Fast & Efficient Construction – Our streamlined process and skilled project management ensure your ADU is completed on time without unnecessary disruptions to your daily life.
3. Superior Craftsmanship & Custom Designs
✅ Aging-in-Place & Accessibility Features – Our ADUs are designed with the future in mind, incorporating accessibility features such as wider doorways, step-free entrances, and senior-friendly layouts for long-term convenience.
✅ Tailored Solutions for Every Home – Every family’s needs are unique, which is why we create custom ADU designs that maximize space efficiency, match your home’s aesthetics, and fit your lifestyle.
✅ High-Quality Materials & Precision Engineering – We use only top-tier materials sourced from our trusted, high-quality suppliers, ensuring that your ADU is durable, safe, and built to last for generations.
4. A Lifestyle Solution for Your Family's Needs
✅ Keep Loved Ones Close – Give elderly parents or adult children a private yet nearby living space, ensuring family members stay connected while maintaining their independence.
✅ Multigenerational Living Made Easy – Whether it's providing a comfortable home for aging parents or giving young adults a head start, our ADUs foster a supportive and practical living arrangement.
✅ Enhance Your Home’s Functionality – More than just extra space, an ADU can serve as a dedicated home office, personal gym, creative studio, or even a guest house for visiting relatives and friends.
About Us
Partners and Affiliations
ADU Builders Group Inc.
ADU Builders Group is a local, family-owned company dedicated to providing innovative solutions to California’s housing crisis, with passion for helping multigenerational families. Having high regards to family-oriented values, our work reflects a deep commitment to creating practical, high-quality custom ADUs that bring loved ones closer while respecting privacy and independence. With heart, craftsmanship, and a focus on community, we build homes that inspire and unite.
✔ Proudly Local
✔ Family-Owned
✔ Licensed and Insured
A Partner & Sister-Company of
Imagine Unique Remodels
Our Services and Expertise
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What's The Best Type of ADU for You?
Our Process
Consult with our ADU Experts
1
To start, discuss your needs, goals, and vision for your ADU with our experts. Start by having a phone consultation with us at (408) 413-3373. We'll set your schedule for the in-person meeting during the call. You'll receive expert recommendations and estimate for your ADU during the consultation phase at no cost.
2
Design with our Architect
Need to customize your ADU based on your needs and requirements? Design your own ADU and turn your ideas into an architectural plan with our Architect.
4
Construct & Pass Inspections
Our Project Managers will be in constant communication with you during construction and will ensure that your projects pass all inspections.
3
Obtain Permits Effortlessly
Our Liaison Officer will take care of the permits for you and work with the city to ensure that all paperworks are in place quickly and efficiently.
5
Enjoy and Maintain your ADU
Live the lifestyle you want and be worry-free. We'll continue to provide support and care to your project with our warranties and annual project inspection.
Local ADU Regulations in Berkeley
Below is an overview of ADU regulations in Berkeley. If you need more details on how these guidelines apply to your property, contact us to get connected with an ADU expert.
Where ADUs Are Allowed
ADUs are generally permitted on properties designated for residential use, though exceptions may apply. Your property must have an existing or planned single-family home or a multi-family building, such as a duplex, triplex, or apartment complex. Reach out to us to confirm if your property qualifies for an ADU.
Minimum Lot Size
There are no minimum lot size restrictions—any property, regardless of its dimensions, may be eligible for an ADU.
Number of ADUs Allowed
Single-family homes can usually accommodate one or two ADUs. Multi-family properties may be eligible for multiple ADUs depending on the number of existing units and the type of ADU constructed. Get in touch with our team to find out how many ADUs your property can support.
Parking Requirements
Conversion and junior ADUs generally do not require additional parking. However, attached and detached ADUs usually need at least one parking space unless an exemption applies. Reach out to us for expert advice on Berkeley’s ADU parking regulations.
Featured Project
ADU Builder Berkeley FAQs
How long does it take to build a small second home in Berkeley?
Most homeowners can expect the full process to take 9 to 14 months. That includes 1–2 months for design, 3–5 months for permits and reviews, and 4–6 months for construction. Projects in hillside zones, historic areas, or fire-prone districts may need additional time for approvals.
What does it cost to build a backyard dwelling in Berkeley?
Costs typically range from $475 to $525 per square foot, depending on size, design, and site complexity. A 750 sq. ft. in-law suite may start around $375,000, while a larger detached structure can easily exceed $500,000. You'll also want to budget for permit fees, utility upgrades, and possible seismic retrofitting for older properties.
Can the secondary unit share utilities with the main house?
Yes, it's common for these compact homes to share water, sewer, and electrical systems with the main residence. That said, many homeowners choose to install separate meters when using the space for rental purposes. If your home is older, upgrading the electrical panel may be necessary.
Are there incentives for building energy-efficient units?
Yes. Berkeley homeowners can take advantage of BayREN energy rebates, solar installation incentives, and EV charger programs. All new construction must follow California Title 24 energy codes, and small units under 750 sq. ft. are exempt from local impact fees.
Why are more people building accessory units in Berkeley?
These secondary homes provide flexible, affordable living options for family members, guests, or tenants. They help meet the city’s growing housing needs without changing neighborhood character and offer a way for homeowners to generate passive income or support multi-generational living.
Is there a strong interest in compact dwellings in Berkeley?
Yes—demand is high due to limited housing supply, rising rents, and growing interest in flexible living arrangements. Homeowners are using these spaces for aging relatives, young adults, or as long-term rentals.
What design styles work well in Berkeley?
Popular styles include modern cottages, Craftsman-inspired studios, and eco-conscious micro homes. Features like open layouts, natural lighting, smart home systems, and private outdoor areas are frequently requested to maximize comfort and function.
Where can I find guidance on building a second unit?
The City of Berkeley Planning & Development Department offers resources like zoning maps, application checklists, and design standards on its website. You can also visit the Permit Service Center for help navigating the process.
How do these units affect Berkeley neighborhoods?
When designed thoughtfully, they provide low-impact housing that blends into existing residential areas. The city has rules on height, setbacks, privacy, and design to ensure these homes are compatible with their surroundings, especially in historic or architecturally sensitive areas.
Do I need to add parking for a guest unit?
Not necessarily. If the space is within ½ mile of public transit, or if you're converting part of the existing home or garage, no additional parking is required. For all other situations, one off-street space may be needed.
Service Areas
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