Smarter ADUs for Bay Area Living
We’re a team of licensed builders and designers helping homeowners unlock new space, income, and freedom through custom-built ADUs.
Built local. Designed smart.
At ADU San Mateo, we combine architectural insight, construction experience, and deep knowledge of Bay Area zoning laws to deliver high quality accessory dwelling units from design through move in. Our mission is simple: to make building your ADU clear, fast, and stress free.
Our San Mateo office
3 E 3rd Ave, Suite 200
Our Mission & Values
Our mission is to simplify the ADU journey for every homeowner from concept to move in, grounded in craftsmanship, transparency, and local expertise.
Transparency
Tailored project design approach, specifically created for your home.
Local Knowledge
We handle all city approvals and paperwork to ensure a stress free, on time process.
Craftsmanship
Quality construction using modern materials and experienced local crews.
Sustainability
Turnkey results so your ADU is ready to live in, rent out, or welcome guests.
Elie AlChaer
Founder & Licensed General Contractor
Meet Our Founder
Elie AlChaer founded ADU San Mateo to fix a problem he kept seeing in residential construction: waste. Homeowners hire the cheapest bid, the cheapest bid makes mistakes, and the mistakes cost more than doing it right would have, in time, money, and stress.
Elie's background is the opposite of that model. He spent his career in senior delivery roles on more than $2 billion of commercial and luxury projects across the Bay Area and Dubai, from high-rise office towers to life sciences labs, for owners who accept nothing less than on-time and on-budget delivery.
ADU San Mateo applies that discipline to backyard homes. The team studied the full ADU process (permitting, design, budgeting, and construction) and broke it into clear phases. You pay for one phase at a time, and each phase gives you exactly what you need to decide whether and how to move forward. No over-committing to the entire project before you know it pencils. It's the same phased, progressive approach used on sophisticated commercial projects, translated for homeowners.
Services
Ask us about our tier options and find the right fit for your ADU project.
End-to-end ownership from concept through completion
ASM manages design, engineering, and permit coordination
Client handles planning, design, and engineering directly
Currently Working In
Providing reliable, high-quality services across your region.
Counties
- San Mateo County
- Santa Clara County
Cities
- Atherton
- Millbrae
- Burlingame
- Hillsborough
- Menlo Park
- San Carlos
- San Mateo
- Belmont
- Foster City
- Redwood City
- Daly City
- Pacifica
- South San Francisco
- Saratoga
- Los Gatos
- Palo Alto
- Los Altos
- Cupertino
- Willow Glen
Testimonials & Reviews
Real reviews from Bay Area homeowners we’ve built for.
“I am so happy to find ADU San Mateo. The crew are nice, professional, doing a great job while pay attention to details, all with a good price. Highly recommend!”
“Finished work in a timely fashion. Quick to respond.”
“Excellent service highly recommended”
“ADU San Mateo went above and beyond our expectations. They were with us every step of the project, making the experience easy and headache free. ADU San Mateo has great attention to detail and abundance of carpentry knowledge. They always answered our calls and ensured the job site was clean and safe before ending the workday. The team was very professional, clean, and respectful. We contracted ADU San Mateo to build our ADU unit and cannot be happier with the outcome. Would definitely recommend to anyone looking for cost-effective get it right the first time company. Definitely would use for our future projects.”
“Dependable, responsive, quality workmanship and dedication to getting the project completed timely and on or under budget. They treated our home as if it was their own. The outcome exceeded my expectations. Would recommend to my friends and family.”
“I would highly recommend ADU San Mateo to all my friends and family. The crew is efficient, polite and hardworking. They are easy to work with and very competitive with pricing. We would definitely recommend and hire again for future projects.”
“Such exceptional work done, I am beyond pleased with the results! Paid close attention to detail and I was always kept informed. High quality work and excellent service gave us the results we expected. I was completely impressed with their professionalism and customer service. I highly recommend this business!”
“I HIGHLY recommend Eli and his team for any home remodeling projects. They did my staircase and completely did what I have envisioned. I am a perfectionist, so I am glad I met them. They are very detailed oriented, very punctual, and there were no delays. He advised me what’s the best route, up to code, and provided recommendations tweaks on my design. I provided a 3D rough draft sketch to them, the measurements were 100% accurate. I can guarantee you that you won’t be disappointed, as I went through roughly 10 contractors and FINALLY found the right team. I am looking forward to seeing how my kitchen tiles turn out.”
“They were responsive and efficient and easy to work with.”
Your dream ADU starts here
Free feasibility review, no-obligation consultation, response within 1 business day.