How Much Does a Garage Conversion Cost in San Jose? (2026)
Garage conversions in San Jose cost $100,000 to $180,000+ in 2026, depending on size, conversion type, and finish level. As the Bay Area's largest city, San Jose offers some of the most accessible garage conversion pricing in the region while still benefiting from strong rental demand and property values. Full ADU conversions with kitchen and bathroom run $120,000-$180,000+. Simpler conversions like home offices or guest rooms cost $70,000-$110,000.
How much does a garage conversion cost in San Jose?
A garage conversion in San Jose costs $100,000 to $180,000+ in 2026. Basic conversions (home office, guest room) start at $70,000-$110,000. Full ADU conversions with kitchen and bathroom run $120,000-$180,000+. San Jose's pricing is generally 5-10% below premium South Bay cities like Saratoga and Los Gatos.
What Does a Garage Conversion Cost in San Jose?
San Jose is the Bay Area’s most populous city, with over a million residents and a housing market that spans every price point. The city’s strong rental demand, fueled by tech employment and a persistent housing shortage, makes garage conversions one of the most practical investments available to homeowners. Whether you need a rental unit for income, a home office for remote work, or a guest suite for visiting family, converting an underused garage puts existing space to productive use.
In 2026, San Jose garage conversions cost $100,000 to $180,000+ for a full ADU conversion and $70,000 to $110,000 for simpler conversions like home offices or guest rooms. San Jose’s pricing generally falls 5-10% below premium South Bay communities like Saratoga and Los Gatos, making it one of the more accessible markets for this type of project.
All pricing is approximate, reflects 2026 Bay Area market conditions, and is subject to change. Every project is unique. Final costs are determined on a project-by-project basis during our design phase.
For a broader regional perspective, see our Bay Area garage conversion cost guide.
Cost Breakdown by Conversion Type
| Conversion Type | Cost Range | Timeline | What Is Included |
|---|---|---|---|
| Full ADU (Rental Unit) | $120,000-$180,000+ | 4-6 months | Kitchen, full bathroom, bedroom area, HVAC, electrical upgrade, plumbing, insulation, finishes, separate entrance |
| Home Office / Studio | $70,000-$110,000 | 3-4 months | Insulation, drywall, flooring, electrical upgrade, HVAC, windows, lighting, data/network wiring |
| Guest Suite | $90,000-$140,000 | 3-5 months | Bedroom space, full bathroom, insulation, flooring, HVAC, closet, separate entrance |
| In-Law / Caretaker Unit | $125,000-$190,000+ | 4-7 months | Full kitchen, bathroom, ADA features as needed, separate entrance, laundry hookups, HVAC |
The biggest cost jump happens when you add plumbing. A home office without water connections saves $15,000-$30,000 compared to a full ADU with kitchen and bathroom. Once plumbing enters the scope, you need supply lines, drain connections, a water heater, and fixtures, all of which add cost and complexity.
Detailed Cost Components
Understanding where your budget goes helps you make smarter decisions. Here is a typical component breakdown for a full ADU garage conversion in San Jose.
Construction Costs ($70,000-$120,000)
| Component | Cost Range | Notes |
|---|---|---|
| Structural work and framing | $6,000-$15,000 | Garage door replacement with framed wall, header modifications |
| Insulation and drywall | $4,000-$9,000 | Walls, ceiling, vapor barrier to meet Title 24 |
| Electrical upgrade | $6,000-$12,000 | New subpanel, circuits, outlets, lighting |
| Plumbing | $8,000-$20,000 | Kitchen and bathroom supply/drain lines, water heater, fixtures |
| HVAC | $4,000-$10,000 | Mini-split system is the most common choice |
| Flooring | $3,000-$8,000 | Slab leveling, moisture barrier, finished flooring |
| Kitchen | $10,000-$25,000 | Cabinetry, countertops, appliances, sink |
| Bathroom | $8,000-$20,000 | Tile, vanity, toilet, shower, ventilation |
| Windows and doors | $4,000-$10,000 | Egress windows, entry door, and optional slider |
| Finishes and trim | $4,000-$10,000 | Paint, baseboards, hardware, lighting fixtures |
Soft Costs ($12,000-$40,000)
| Category | Cost Range | Notes |
|---|---|---|
| Architectural plans | $5,000-$15,000 | Required for permit submission |
| Engineering | $2,000-$8,000 | Structural, if needed for garage door wall replacement |
| Permit fees | $3,000-$12,000 | Building, plumbing, electrical, mechanical |
| Title 24 energy calculations | $500-$1,500 | Required for permit |
| Utility connections | $1,500-$5,000 | Separate electrical meter, sewer connection fees |
Total Project Costs by Garage Size
| Garage Type | Typical Size | ADU Conversion Cost | Non-Plumbing Conversion Cost |
|---|---|---|---|
| Single-car garage | 200-250 sqft | $100,000-$150,000 | $70,000-$100,000 |
| Two-car garage | 400-500 sqft | $130,000-$200,000+ | $85,000-$130,000 |
| Oversized two-car | 500-600 sqft | $150,000-$220,000+ | $95,000-$140,000 |
What Drives Costs in San Jose
Neighborhood Variation
San Jose’s size creates meaningful cost differences by neighborhood:
| Neighborhood | Cost Premium | Rental Income Potential | Notes |
|---|---|---|---|
| Willow Glen | +5-10% | $2,200-$2,800/mo | Higher finish expectations, walkable to downtown |
| Almaden Valley | +5-10% | $2,000-$2,600/mo | Larger garages, family-oriented tenants |
| Rose Garden | +5-10% | $1,800-$2,400/mo | Older homes, potential structural upgrades needed |
| Cambrian | Baseline | $1,600-$2,200/mo | Straightforward conversions, good rental demand |
| Berryessa | Baseline | $1,500-$2,000/mo | Strong demand near BART station |
| Evergreen | Baseline | $1,500-$2,100/mo | Newer garages, often in better condition |
Garage Condition
The existing condition of your garage significantly impacts conversion costs:
- Good condition (post-1990, no damage): Minimal structural work needed; saves $5,000-$15,000
- Fair condition (1970s-1980s, minor issues): Some foundation repair, framing corrections; adds $5,000-$10,000
- Poor condition (pre-1970, significant deterioration): Major structural work, possible foundation replacement; adds $15,000-$30,000+
Slab and Foundation Work
Garage slabs are typically thinner than residential foundations and may slope toward the garage door for drainage. Converting to livable space often requires:
- Slab leveling or topping: $2,000-$5,000
- Moisture barrier installation: $1,000-$3,000
- Foundation perimeter repair: $3,000-$8,000 if cracked or deteriorated
Permits and Regulations
City of San Jose ADU Permit Process
San Jose has been one of the Bay Area’s most ADU-friendly cities. Key permit details:
- Ministerial review: ADU applications are processed without discretionary review or public hearings
- 60-day processing: State law requires cities to act on complete ADU applications within 60 days
- No parking replacement: Converting an existing garage does not require replacement parking
- No owner-occupancy requirement: You do not need to live on the property to rent out an ADU
- Permit fees: $3,000-$12,000 depending on project scope and utility connections
- Impact fee exemption: ADUs under 750 sqft are exempt from most development impact fees
Building Code Requirements
Your garage conversion must meet current residential building code standards:
- Minimum ceiling height of 7 feet 6 inches (most garages already meet this)
- Egress windows in sleeping areas (minimum 5.7 sqft opening)
- Smoke and carbon monoxide detectors
- Title 24 energy compliance (insulation, windows, HVAC efficiency)
- Fire-rated separation from the main dwelling if the ADU shares a wall
How San Jose Compares to Nearby Cities
| City | Garage Conversion Cost (ADU) | Permit Timeline | Notes |
|---|---|---|---|
| San Jose | $120,000-$180,000+ | 4-8 weeks | Large city, streamlined process |
| Saratoga | $120,000-$200,000+ | 4-8 weeks | Premium market, hillside challenges |
| Los Gatos | $120,000-$200,000+ | 4-8 weeks | Historic overlay, design standards |
| Campbell | $110,000-$170,000 | 4-6 weeks | Smaller city, efficient processing |
| Santa Clara | $110,000-$175,000 | 4-8 weeks | Mid-range market |
| Milpitas | $105,000-$165,000 | 4-8 weeks | Accessible pricing, BART proximity |
San Jose sits in the middle of the regional range, offering a strong balance of reasonable costs and high rental income potential.
Sample Budgets
Budget Example 1: Single-Car Garage to Home Office ($82,000)
| Category | Budget |
|---|---|
| Garage door wall framing | $5,000 |
| Insulation and drywall | $5,500 |
| Electrical (subpanel, outlets, lighting) | $7,000 |
| HVAC (mini-split) | $5,500 |
| Flooring (LVP) | $3,500 |
| Windows (2 egress) | $4,000 |
| Data/network wiring | $2,500 |
| Built-in desk and shelving | $4,000 |
| Paint, trim, finishes | $4,000 |
| Architectural plans | $5,000 |
| Permit fees | $3,500 |
| Title 24 | $800 |
| Contingency (12%) | $6,000 |
| Total | $56,300 |
Budget Example 2: Two-Car Garage to Full ADU ($158,000)
| Category | Budget |
|---|---|
| Structural/framing | $12,000 |
| Insulation and drywall | $8,000 |
| Electrical (subpanel, meter, full circuits) | $11,000 |
| Plumbing (kitchen, bath, water heater) | $18,000 |
| HVAC (mini-split, 2 zones) | $8,000 |
| Flooring | $6,500 |
| Kitchen (cabinets, counters, appliances) | $20,000 |
| Bathroom (tile, vanity, shower, toilet) | $16,000 |
| Windows and entry door | $8,000 |
| Paint, trim, finishes | $7,000 |
| Architectural plans | $8,000 |
| Engineering | $4,000 |
| Permit fees | $8,000 |
| Title 24 and utility connections | $3,500 |
| Contingency (15%) | $19,500 |
| Total | $157,500 |
ROI and Rental Income Potential
San Jose’s rental market makes garage ADU conversions one of the strongest investments available to homeowners.
| ADU Type | Monthly Rent | Annual Income | Payback Period |
|---|---|---|---|
| Studio (250-350 sqft) | $1,500-$2,000 | $18,000-$24,000 | 6-8 years |
| 1-bedroom (400-500 sqft) | $2,000-$2,800 | $24,000-$33,600 | 5-7 years |
With San Jose’s proximity to major tech employers, BART, and VTA light rail, demand for well-built ADU rentals remains consistently strong.
Tips for a Successful San Jose Garage Conversion
1. Check your garage slab first. Have a contractor evaluate the existing slab for cracks, slope, and thickness before planning. Slab issues discovered during construction can add $5,000-$10,000 in unplanned costs.
2. Plan for separate utilities if renting. A separate electrical meter allows you to pass utility costs to the tenant. The upfront cost of $2,000-$4,000 for meter separation pays for itself within the first year of tenancy.
3. Maximize natural light. Garages are dark. Adding egress windows, a slider or French door, and a skylight transforms the space from feeling like a converted garage to feeling like a real living space. This directly impacts both livability and rental value.
4. Do not skip HVAC. San Jose summers are warm. A mini-split system ($4,000-$10,000) provides both heating and cooling and is the most cost-effective HVAC option for a single-room or small-unit conversion.
5. Lock in pricing before construction. A detailed scope and fixed price before construction starts protects you from the change orders that inflate most renovation budgets by 15-20%.
Why San Jose Homeowners Choose Custom Home Design and Build
Custom Home Design and Build has completed garage conversions across San Jose, from Willow Glen to Berryessa to Almaden Valley. Our two-phase design-build process gives you cost certainty and quality control from start to finish.
Phase 1 (Design): We assess your existing garage, develop architectural plans, handle Title 24 calculations, and produce a detailed line-item budget. You see the complete plan and cost before construction begins.
Phase 2 (Build): Our team handles every trade, permit, and inspection. We coordinate with the City of San Jose building department throughout the process.
Start Planning Your San Jose Garage Conversion
Ready to put your garage to better use? Contact our team for a free consultation. We will assess your garage, discuss your goals, and give you a clear picture of costs and timeline before you commit.
Frequently Asked Questions
How much does a full ADU garage conversion cost in San Jose?
A full ADU garage conversion in San Jose costs $120,000 to $180,000+ in 2026. This includes insulation, drywall, flooring, a kitchen or kitchenette, full bathroom, electrical panel upgrade, plumbing connections, HVAC, and interior finishes. Premium finishes, larger two-car garages, and structural upgrades push costs toward the higher end.
Does San Jose require a permit for garage conversions?
Yes. A building permit is required for any garage conversion in San Jose. ADU conversions follow a ministerial approval process under California state law, which means there is no discretionary design review. The city must process complete ADU applications within 60 days. Permit fees range from $3,000 to $12,000 depending on project scope.
Can I convert my garage to an ADU and rent it out in San Jose?
Yes. San Jose allows garage-to-ADU conversions that can be rented to long-term tenants. The city does not require owner-occupancy for ADUs. Rental income for a garage ADU in San Jose ranges from $1,500 to $2,800+ per month depending on size, finish level, and neighborhood. This income can recoup conversion costs within 5-8 years.
Do I need to replace my parking if I convert my garage in San Jose?
No. Under California's ADU laws, San Jose cannot require replacement parking when you convert an existing garage to an ADU. This is one of the biggest cost advantages of garage conversions over new detached ADUs, which may still need to address parking concerns even though the law does not require it.