How Long Does an ADU Take to Build from Start to Move-In in San Jose 2025?

Home » Blog » How Long Does an ADU Take to Build from Start to Move-In in San Jose 2025?

Categories: Uncategorized

Quick Answer: A new detached ADU in San Jose takes 12-24 months total from the initial concept meeting to move-in. The timeline breaks down as: design (2-6 months), permitting (4-12 months from submittal to permit issuance), construction (4-12 months depending on ADU type and size), and final inspection + utility connection (1-2 months). A garage conversion ADU (no new foundation) moves faster — total 9-16 months. The longest phase for most San Jose ADU projects is permitting — the City of San Jose PBCE (Planning, Building and Code Enforcement) has permit processing times that vary between 6 weeks (best case, small ADU) and 8+ months (complex site, corrections required).

ADU Timeline — San Jose 2025 Phase-by-Phase

Helpful Resources:

Phase	Detached ADU (new)	Garage Conversion ADU	Notes
Site feasibility consultation	1-2 weeks	1-2 weeks	Zoning check, setback verification, utility location
Design and architectural drawings	6-12 weeks	4-8 weeks	Floor plan, elevations, site plan, structural details
Engineering (structural + civil)	4-8 weeks	2-4 weeks	Overlaps with architectural in design-build
Permit submittal → first comments	4-12 weeks	3-8 weeks	San Jose PBCE 2025 current processing time
Correction rounds (1-3 typical)	2-8 weeks each	1-4 weeks each	Fewer corrections = faster
Permit issuance after approval	1-2 weeks	1-2 weeks	Fee payment → permit card issued
Foundation work	4-8 weeks	N/A	Footings, stem wall, slab for new structure
Framing	3-6 weeks	1-3 weeks	Structure, roof framing
MEP rough-in (plumbing, electrical, HVAC)	4-8 weeks	3-6 weeks	Inspections at each stage
Insulation + drywall	2-4 weeks	2-3 weeks
Finish work (tile, flooring, cabinets, fixtures)	6-12 weeks	4-8 weeks	Longest finish phase
Final inspection + utility connection	2-6 weeks	2-4 weeks	PG&E/SJ Water connection coordination
Total (typical)	14-24 months	9-16 months

Quartz Construction manages the entire ADU process from design through move-in in San Jose. Learn about ADU construction services. CSLB #1003436 | BBB A+ | 4.9 Stars. Call (650) 749-7436.

Home remodeling project result - Quartz Construction & Remodeling San Jose CA

Watch: San Jose Remodeling Projects by Quartz Construction

Watch: Bay Area Remodeling Insights

Expert tips and real project walkthroughs to help you plan your Bay Area home improvement.

What Our Bay Area Clients Say

4.9 ★ average rating across Google, Yelp, and Houzz from 150+ Bay Area homeowners.

★★★★★

"Quartz Construction did an amazing job on our kitchen remodel. The team was professional, on time, and the results exceeded our expectations. Highly recommend to any Bay Area homeowner!"

— Michael T. | November 15, 2025

★★★★★

"We hired them for a bathroom remodel in our San Jose home. From permitting to final walkthrough, everything was handled perfectly. The tile work is stunning. 5 stars without hesitation."

— Sarah L. | October 28, 2025

★★★★★

"Just finished our ADU garage conversion. The project came in on budget and on schedule — rare in the Bay Area! The rental income already started. Could not be happier with Quartz Construction."

— David R. | December 2, 2025

Read all reviews on Google →

See our latest projects, client photos, and Bay Area remodeling tips:

Google Business Facebook Yelp Instagram Houzz LinkedIn

Get a Free Estimate

Licensed Bay Area contractor — CSLB #1003436 — serving San Jose, Fremont, Oakland, Santa Clara, Sunnyvale and all Bay Area communities.

Call: (650) 749-7436

📚 Additional Resources: California HCD — ADU Information • California Contractors State License Board

Get a Free Estimate from Quartz Construction

Licensed General Contractor • CSLB Lic#1003436 • Serving San Jose, Santa Clara & Bay Area

Google Reviews — What Our Clients Say

      
   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