How much does an ADU cost in Orinda?

ADU construction in Orinda costs $150,000–$400,000 for a detached ADU. Garage conversions run $60,000–$120,000. JADUs start at $40,000. Costs vary by size, finishes, and permitting. Quartz Construction provides free ADU estimates.

How long does ADU construction take in Orinda?

ADU projects in Orinda typically take 4–10 months including permitting (2–4 months) and construction (3–6 months). Pre-approved ADU plans can reduce permitting time significantly.

What ADU types are allowed in Orinda?

California law allows detached ADUs, attached ADUs, garage conversions, and junior ADUs (JADUs) in Orinda. SB 9 and AB 2221 expanded ADU rights statewide. Quartz Construction handles all ADU types and full permit processing.

What is the rental income potential of an ADU in Orinda?

ADU rental income in Orinda ranges $2,000–$4,500/month depending on size and amenities. At these Bay Area rents, most ADUs achieve positive ROI within 5–8 years. Quartz Construction builds ADUs designed to maximize rental appeal.

Is Quartz Construction licensed to build ADUs in Orinda?

Yes. Quartz Construction holds CSLB #1003436 and is BBB A+. We have built 50+ ADUs across the Bay Area including Orinda. Call (650) 749-7436 for a free ADU consultation.

ADU Construction Orinda CA | Quartz Construction | CSLB #1003436

ADU Construction in Orinda, Contra Costa | Quartz Construction

Quartz Construction builds accessory dwelling units (ADUs) in Orinda — from design and permits through complete construction. Whether you want to add a backyard ADU for rental income, house family members, or create a home office, we handle the entire project as your licensed general contractor. CSLB #1003436 | BBB A+ | 4.9 Stars.

ADU Types We Build in Orinda

Industry Resources & Standards:

Detached ADU: A fully separate dwelling in the backyard — the most popular type in Orinda. Complete privacy for the main house and the ADU occupants
Attached ADU: An addition connected to the main house with its own entrance. Less expensive than detached when sharing walls reduces framing cost
Garage conversion ADU: Converting an existing attached or detached garage into livable ADU space. Fast and cost-effective if the existing structure is sound
Junior ADU (JADU): Up to 500 sq ft within the existing single-family home footprint with a separate entrance. No setback requirements under California law

ADU Cost in Orinda 2025

ADU Type	Size	Cost Range
Junior ADU (JADU)	Up to 500 sq ft	$60,000 – $130,000
Garage conversion	400–600 sq ft	$90,000 – $180,000
Attached ADU	400–800 sq ft	$200,000 – $380,000
Detached ADU	500–1,200 sq ft	$250,000 – $500,000+

A 1-bedroom ADU in Orinda and Contra Costa County can generate $2,500–$4,000/month in rental income. Call Quartz Construction for a free ADU feasibility consultation: (650) 749-7436 | ADU services | Free estimate

What Our Clients Say

Join hundreds of happy Bay Area homeowners who trusted Quartz Construction & Remodeling for their projects.

      
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   Perry Finch 
 
 
 
 Trustindex verifies that the original source of the review is Google. We’re so happy with the work Hila and her team did on our home addition. The new space flows beautifully with the existing structure, and the quality is clear in every finish. Finished on schedule and stress-free.
  
 
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   Joy Ruther 
 
 
 
 Trustindex verifies that the original source of the review is Google. Working with Ohad on our full home remodel was an incredible experience. He helped us through every decision and made sure everything turned out exactly how we envisioned. The team was easy to communicate with and super detail-focused. We still can’t believe how beautiful our home looks!
  
 
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   Ajay Mukhopadhyay 
 
 
 
 Trustindex verifies that the original source of the review is Google. We recently worked with Quartz Construction (Owner: Ohad) for a construction project to remodel our Bathroom and we couldn’t be more pleased with the results. From start to finish, their team demonstrated professionalism, and exceptional craftsmanship. They maintained clear communication throughout the project, kept us informed of progress and any potential changes, and delivered everything on time and within budget. Their quality of work is outstanding — every detail was handled with care and precision. What stood out most was their commitment to customer satisfaction. They were responsive to our questions, respectful of our space, and ensured that the final outcome matched our vision perfectly. If you're looking for a reliable, skilled, and trustworthy construction contractor, I wholeheartedly recommend Quartz Construction ( Ohad and his team) .They exceeded our expectations in every way. Ajay
  
 
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   debbie curley 
 
 
 
 Trustindex verifies that the original source of the review is Google. I had a fantastic experience working with Quartz Construction And Remodeling. Ohad Maloul the owner was professional communicative and a pleasure to work with from start to finish. His team repaired and painted my backyard pergola and the quality of their work was truly excellent. They were always on time, friendly and responsive to any questions I had throughout the process. I appreciated the clear communication and attention to detail. I’m excited to work with Ohad and his team on future projects and highly recommend them to anyone looking for reliable, high-quality construction or remodeling services.
  
 
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   Harry Lewis 
 
 
 
 Trustindex verifies that the original source of the review is Google. Hila managed our balcony addition project with care and precision. The design complements our home perfectly, and the build quality is outstanding. She communicated every step and made the whole process easy. We’re thrilled with the result!
  
 
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   Qi Lei 
 
 
 
 Trustindex verifies that the original source of the review is Google. I had the chance to work with Ohad and his construction team on a recent home project, and I was really impressed. Ohad is professional, easy to communicate with, and genuinely cares about the quality of the work. The crew showed up on time, kept the work area clean, and finished the job on schedule. It’s hard to find contractors who are reliable and transparent these days, but Ohad delivered on everything he promised. Would definitely recommend if you’re looking for someone who takes pride in their work and keeps things straightforward.
  
 
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   Boris Tyron 
 
 
 
 Trustindex verifies that the original source of the review is Google. We’re so happy with the work Quartz Construction did on our backyard. Ohad’s team designed and built a gorgeous deck and patio that turned the area into a dream space. The quality and detail are fantastic. Highly recommend!
  
 
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   Gloria Collin 
 
 
 
 Trustindex verifies that the original source of the review is Google. Quartz Construction built the most beautiful pergola in our backyard, thanks to Ohad. He was easy to work with, listened to our needs, and delivered a structure that’s both stylish and durable. We now have a shaded space where we can relax and entertain guests.
  
 
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   Dustin Walsh 
 
 
 
 Trustindex verifies that the original source of the review is Google. They built a beautiful, durable pergola that fits our outdoor space perfectly. Hila paid close attention to both style and quality. We now have the perfect spot for lounging, gatherings, and enjoying every season.
  
 
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   Paul Wilins 
 
 
 
 Trustindex verifies that the original source of the review is Google. We feel incredibly lucky to have worked with Hila. She made the ADU process simple and stress-free, handling everything with care and professionalism. The final space is perfect—efficient, elegant, and exactly what we hoped for. Big thanks to her and the whole crew!
  
 
  
  
 
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