ADU Construction in Walnut Creek, CA | Backyard ADUs & Garage Conversions

ADU Construction in Walnut Creek, CA

Quartz Construction builds accessory dwelling units (ADUs) in Walnut Creek, CA. Whether you need a detached backyard ADU, a garage conversion, or a junior ADU, our licensed team handles everything — design, permits, and construction. Licensed CSLB #1003436 | BBB A+ | 4.9⭐ (65+ Reviews)

ADU Types We Build in Walnut Creek

Industry Resources & Standards:

Detached Backyard ADU — Separate, self-contained unit in your backyard. Ideal for rental income or family member housing.
Attached ADU — Addition to your existing home with separate entrance and utilities.
Garage Conversion ADU — Transform your Walnut Creek garage into a fully permitted living space at lower cost.
Junior ADU (JADU) — Smaller unit within your existing home structure, permitting often simpler.
Above-Garage ADU — Second-story unit built over your existing garage.

ADU Cost in Walnut Creek

ADU construction in Walnut Creek costs $150,000–$340,000 for a detached ADU. Garage conversions are more affordable at $60,000–$120,000. The high cost of housing in Walnut Creek means a well-built ADU typically rents for $2,500–$4,500/month, achieving full ROI in 5–8 years.

ADU Permits in Walnut Creek

California state law (AB 2221, SB 9) allows ADUs on all single-family lots, including in Walnut Creek. Walnut Creek has streamlined its ADU permit process in compliance with state mandates. Quartz Construction handles all permitting, engineering, and inspections — you don’t need to navigate City Hall alone.

ADU Rental Income in Walnut Creek

ADU rental income in Walnut Creek typically ranges $2,200–$4,000/month depending on size and finishes. With Bay Area rents this high, most Walnut Creek homeowners recoup their ADU investment within 6–8 years while simultaneously increasing their property value by $200,000–$400,000+.

Get a Free ADU Estimate in Walnut Creek

Ready to build an ADU in Walnut Creek? Quartz Construction provides free ADU consultations including site assessment, permit feasibility review, and construction estimate. Call (650) 749-7436 or fill out our contact form. CSLB #1003436 | BBB A+ | Serving Walnut Creek and all Bay Area cities.

Call (650) 749-7436

Free ADU Estimate

What Our Clients Say

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

      
   Quartz Construction
   65 Google reviews 
  Write a review 
  
 
 
   
 
 
       Posted on Google  
   
   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.
  
 
      Posted on Google  
   
   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!
  
 
      Posted on Google  
   
   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
  
 
      Posted on Google  
   
   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.
  
 
      Posted on Google  
   
   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!
  
 
      Posted on Google  
   
   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.
  
 
      Posted on Google  
   
   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!
  
 
      Posted on Google  
   
   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.
  
 
      Posted on Google  
   
   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.
  
 
      Posted on Google  
   
   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!
  
 
  
  
 
     Verified by Trustindex  Trustindex verified badge is the Universal Symbol of Trust. Only the greatest companies can get the verified badge who has a review score above 4.5, based on customer reviews over the past 12 months. Read more

Professional Resources & Regulations

California Contractors State License Board (CSLB) — Verify contractor licenses
City of San Jose Building Permits — Permit requirements & inspections
ENERGY STAR — Energy-efficient materials & standards

What our clients say on Google

Verified reviews from our Google Business Profile. See all reviews on Google.

      
   Quartz Construction
   65 Google reviews 
  Write a review 
  
 
 
   
 
 
       Posted on Google  
   
   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.
  
 
      Posted on Google  
   
   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!
  
 
      Posted on Google  
   
   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
  
 
      Posted on Google  
   
   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.
  
 
      Posted on Google  
   
   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!
  
 
      Posted on Google  
   
   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.
  
 
      Posted on Google  
   
   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!
  
 
      Posted on Google  
   
   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.
  
 
      Posted on Google  
   
   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.
  
 
      Posted on Google  
   
   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!
  
 
  
  
 
     Verified by Trustindex  Trustindex verified badge is the Universal Symbol of Trust. Only the greatest companies can get the verified badge who has a review score above 4.5, based on customer reviews over the past 12 months. Read more

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