ADU & Home Additions in San Jose
Add living space, rental income, or multigenerational housing to your San Jose property — expertly designed and permitted.
How Much Does ADU & Home Additions Cost in San Jose?
Garage conversions on the lower end. Detached 1,200 sq ft ADUs with premium finishes at the higher end.
Every project is unique. We provide a fixed-price contract after your free consultation — no hidden fees, no cost-plus surprises. The price you agree to is the price you pay.
What to Know About ADU & Home Additions in San Jose
Local building codes, neighborhood character, and permit requirements vary by city. Here's what San Jose homeowners should know before starting a project.
- 01San Jose allows ADUs up to 1,200 sq ft on single-family lots and has eliminated parking requirements for ADUs within a half-mile of public transit — which covers much of the city
- 02The City of San Jose offers pre-approved ADU plans that can reduce permitting time to 2-3 weeks, but custom designs typically take 6-10 weeks through plan check
- 03San Jose's SJ Permit Center on North First Street offers over-the-counter ADU consultations — Barcci Builders can coordinate pre-application meetings on your behalf
- 04Almaden Valley and parts of South San Jose have larger lots (8,000-15,000+ sq ft) that accommodate generous detached ADUs with private yards
- 05San Jose charges development impact fees for ADUs over 750 sq ft, typically $5,000-$15,000 depending on unit size — we include these in our project budgets
Our ADU & Home Additions Process
A clear, structured approach from your first call to final reveal.
Feasibility Assessment
We evaluate your property, zoning, and lot coverage to determine what's possible and what will deliver the best ROI.
Design & Engineering
Our architects create plans that maximize space, light, and livability while meeting all local building codes.
Permits & Approvals
We navigate the full permitting process — city planning, building department, and utility coordination.
Construction
Our experienced crew builds your ADU with the same quality standards as our luxury home remodels.
Inspection & Handover
We manage all inspections, obtain the certificate of occupancy, and walk you through your completed ADU.
ADU & Home Additions in San Jose: FAQ
Answers to common questions from San Jose homeowners.
A typical San Jose ADU takes 5-8 months from permit submission to move-in. Permitting takes 6-10 weeks for custom designs (faster with pre-approved plans), and construction runs 4-6 months depending on size and complexity. Garage conversions are faster — typically 3-4 months of construction.
A well-built one-bedroom ADU in San Jose typically rents for $2,200-$3,000 per month depending on neighborhood, size, and finishes. Two-bedroom units command $2,800-$3,800. Almaden Valley, Willow Glen, and Rose Garden ADUs command premium rents due to neighborhood desirability.
Most San Jose single-family lots can accommodate a detached ADU. The key factors are lot size, existing lot coverage, setback requirements (4 feet from side and rear property lines), and utility access. We provide a free site feasibility assessment to determine your property's ADU potential.
No. San Jose does not require owner-occupancy for properties with ADUs. You can rent both your primary home and your ADU, or live in the ADU and rent the main house. This flexibility makes ADUs an excellent investment strategy.
Yes, and it's one of the most cost-effective ADU options. San Jose allows garage conversions and does not require you to replace the lost parking spaces. A typical two-car garage conversion yields a comfortable 400-500 sq ft studio or one-bedroom unit.
A Junior ADU (JADU) is created within the existing footprint of your home — typically by converting a bedroom or attached garage — and is limited to 500 sq ft. A standard ADU can be up to 1,200 sq ft and can be detached. San Jose allows both a JADU and an ADU on the same property, giving you up to three units total.
More Services in San Jose
Explore our other design-build services available in San Jose.
Ready to Start Your San Jose ADU & Home Additions?
Book a free in-home consultation. We'll discuss your vision, walk through your space, and provide a detailed fixed-price estimate — no pressure, no obligation.