Quick Answer: A home addition project in San Jose goes through these phases in order: (1) Design and engineering — 4-8 weeks to draw plans and get structural engineering; (2) Permit application and approval — 4-10 weeks for San Jose building department review; (3) Site preparation — clearing, demolition of any existing structure, erosion control; (4) Foundation — excavation, forms, rebar, concrete pour, and cure (2-4 weeks); (5) Framing — walls, floor system, roof structure (1-3 weeks); (6) Rough mechanical — plumbing, electrical, HVAC ductwork run through walls and ceiling before drywall (2-3 weeks); (7) Insulation and Title 24 — Title 24 energy compliance verification before calling for inspection; (8) Drywall — hanging, taping, texture, prime (1-2 weeks); (9) Finish work — flooring, cabinets, trim, paint, fixtures (2-4 weeks); (10) Final inspection and certificate of occupancy. Total timeline: 6-12 months from design start to move-in for a typical room addition.
Home Addition Timeline — San Jose 2025
| Phase | Duration | Key Milestone |
|---|---|---|
| Design and structural engineering | 4-8 weeks | Signed and stamped permit-ready drawings |
| Permit application and approval | 4-10 weeks | Approved permit in hand |
| Site prep and demolition | 1-2 weeks | Foundation excavation complete |
| Foundation (concrete) | 2-4 weeks | Foundation inspection passed |
| Framing | 1-3 weeks | Framing inspection passed |
| Rough plumbing, electrical, HVAC | 2-3 weeks | Rough MEP inspections passed |
| Insulation (Title 24 compliance) | 1 week | Insulation inspection passed |
| Drywall | 1-2 weeks | Drywall hang, tape, texture complete |
| Finish work (floors, paint, fixtures) | 2-4 weeks | Certificate of Occupancy issued |
| Total | 4-9 months construction | Certificate of Occupancy |
Quartz Construction manages the entire room addition process in San Jose — from design through final inspection. We assign a project manager to every addition. Learn about room addition services. CSLB #1003436 | Call (650) 749-7436.
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. |
"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. |
"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. |
Follow Us
See our latest projects, client photos, and Bay Area remodeling tips:
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
Get a Free Estimate from Quartz Construction
Licensed General Contractor • CSLB Lic#1003436 • Serving San Jose, Santa Clara & Bay Area
