
ADU Builder Los Altos Hills
Custom, High-Quality Accessory Dwelling Units
Are you looking to build an Accessory Dwelling Unit (ADU) in Los Altos Hills, 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 Los Altos Hills, 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 Los Altos Hills 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 Los Altos Hills' 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
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

Our Services and Expertise
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 Los Altos Hills
Below is an overview of Los Altos Hills' ADU regulations. If you need more details on how these rules apply to your property, reach out to us to connect with an ADU expert.
Where ADUs Are Allowed
ADUs are typically permitted on residentially zoned properties, though some 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. Contact us to confirm whether your property is eligible for an ADU.
Minimum Lot Size
There are no minimum lot size restrictions—properties of any size may qualify for an ADU.
Number of ADUs Allowed
Single-family homes can typically have one or two ADUs, while multi-family properties may qualify for multiple ADUs based on the number of existing units and the type of ADU being built. Get in touch with our team to find out how many ADUs your property can accommodate.
Parking Requirements
Conversion and junior ADUs generally do not require additional parking. However, attached and detached ADUs typically require at least one parking space unless an exemption applies. Reach out to us for expert guidance on parking requirements for ADUs in Los Altos Hills.
Featured Project
ADU Builder Los Altos Hills FAQs
How long does it take to build a guest house or in-law unit in Los Altos Hills?
Most projects take 9 to 14 months, depending on complexity. This includes 2–3 months for design, 3–5 months for permits and planning approvals, and 4–6 months for construction. In hillside areas or on larger parcels, additional time may be needed for grading, septic evaluations, or design review.
What’s the average cost to build a compact dwelling here?
Costs typically range from $500 to $550 per square foot, reflecting the area’s preference for high-quality finishes and custom construction. A 750 sq. ft. backyard cottage or in-law suite might start around $400,000, with larger or more customized structures easily exceeding $600,000.
Can the new space share utilities with the primary home?
Yes, smaller dwellings often connect to the existing water, sewer (or septic), and electrical systems. If the unit will be rented, separate utility meters may be recommended. Many rural properties rely on septic systems, which may need upgrades to support a second structure.
Are there any energy-efficiency or sustainability incentives available?
Yes. Homeowners in Los Altos Hills can access BayREN rebates, along with solar panel incentives, EV charger support, and appliance efficiency programs. All new construction must comply with California’s Title 24 energy standards, and homes under 750 sq. ft. are generally exempt from certain development impact fees.
Why are residents adding secondary living spaces?
These smaller homes offer flexibility for multigenerational living, live-in caregivers, or long-term guests. They provide privacy and comfort without requiring the homeowner to expand the main house, making them ideal for aging in place or hosting family.
Is there growing demand for guest cottages in Los Altos Hills?
Yes. Many residents are choosing to build private suites, detached garden flats, or converted garages to accommodate family needs or future planning. These homes also offer discreet additional space on larger properties without altering the estate feel.
What types of styles are most common?
Designs often match the main residence, with preferences leaning toward Mediterranean, modern ranch, or transitional architecture. Popular features include vaulted ceilings, covered patios, energy-efficient systems, and panoramic windows that blend with the surrounding landscape.
Where can I find planning guidance and permitting help?
The Town of Los Altos Hills Planning Department offers detailed documents on zoning, setbacks, height limits, and development standards. For personalized support, schedule a pre-application meeting to explore your site’s potential.
Will building a secondary unit change the character of the property?
Not significantly. The town has strict requirements to preserve its low-density, rural atmosphere. New construction must meet guidelines for privacy, landscaping, architecture, and site integration, ensuring harmony with neighboring properties.
Is additional parking required?
In most cases, one off-street space is required for a new unit. However, requirements may vary depending on the size of the lot, access to transit, or if you're converting an existing garage or accessory structure.
Service Areas
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