Garage Conversion Cost Calculator
Estimated Total Cost
$5,000 – $10,000
$25 – $50 per sq ft
Base Conversion
$5,000 – $10,000
Bathroom
None
HVAC
None
Cost Per Sq Ft
$25 – $50
Permit Required: Most cities require a building permit for garage conversions ($500–$2,000). ADUs have additional zoning requirements. Always check with your local building department before starting.
Additional costs not included: Garage door wall conversion ($1,500–$5,000), electrical subpanel upgrade ($1,000–$3,000), insulation (R-13+ walls required, $1–$3/sqft), flooring ($2–$8/sqft), permits ($500–$2,000), and site prep/grading.
Disclaimer: Estimates are for budgeting purposes only. Actual costs vary by location, contractor, material availability, and project complexity. Always get professional quotes for exact pricing.
Garage Conversion Cost Breakdown
| Conversion Type | Cost Per Sq Ft |
|---|---|
| Basic Living Space | $25 – $50 |
| Home Office | $25 – $50 |
| Bedroom | $30 – $60 |
| ADU (Full Apartment) | $100 – $300 |
* Base conversion cost only. Does not include bathroom, HVAC, or garage door wall conversion.
Average Project Costs
| Project Configuration | Total Cost |
|---|---|
| Single Car Basic (200 sqft, no bath, no HVAC) | $5,000 – $10,000 |
| Single Car Bedroom (200 sqft, half bath, mini-split) | $11,000 – $28,000 |
| Double Car Basic (400 sqft, no bath, no HVAC) | $10,000 – $20,000 |
| Home Office (200 sqft, mini-split) | $7,000 – $18,000 |
| ADU Conversion (400 sqft, full bath, kitchen, ducted HVAC) | $53,000 – $160,000 |
* Includes base conversion, bathroom, and HVAC where specified. Does not include garage door wall conversion, permits, or finish upgrades.
How We Calculate
Our garage conversion cost calculator estimates total project cost based on square footage, conversion type, bathroom additions, and HVAC systems. Total cost = base conversion cost + bathroom cost + HVAC cost.
How the math works: Base conversion costs $25–$60/sqft depending on finish level (basic living space vs bedroom vs office). ADU conversions cost significantly more at $100–$300/sqft due to kitchen requirements, higher finish standards, and code compliance. Bathroom additions are flat costs ($3,000–$8,000 for half bath, $8,000–$25,000 for full). HVAC ranges from $200 for a window unit to $15,000 for a full ducted system.
Conversion Type Comparison
Basic Living Space ($25–$50/sqft) includes flooring, drywall, paint, lighting, and electrical outlets. Bedroom ($30–$60/sqft) adds a closet, egress window, and upgraded finishes. Home Office ($25–$50/sqft) includes enhanced electrical for equipment and data wiring. ADU ($100–$300/sqft) is a full apartment with kitchen, bathroom, separate entrance, and independent utilities.
Bathroom Addition Costs
Half bath ($3,000–$8,000) includes toilet, sink, ventilation, and basic finishes. Full bath ($8,000–$25,000) adds a shower or tub with tile surrounds, upgraded fixtures, and more extensive plumbing. Costs increase with high-end fixtures, custom tile work, and if the existing concrete slab needs cutting for drainage.
HVAC Options
No HVAC works in mild climates for occasional-use spaces. Window unit ($200–$500) is the budget option but less efficient. Mini-split ($2,000–$8,000) offers efficient heating and cooling without ductwork — ideal for single rooms. Ducted system ($5,000–$15,000) extends central HVAC but may require upgrading the main unit for capacity.
Additional Costs
Our estimates cover core conversion work. Additional costs include: garage door wall conversion ($1,500–$5,000), electrical subpanel ($1,000–$3,000), insulation to R-13+ ($1–$3/sqft), flooring ($2–$8/sqft), permits ($500–$2,000), egress window for bedrooms ($1,500–$5,000), and architectural plans ($500–$2,500).
Data Sources
Pricing data is compiled from HomeAdvisor, Angi, HomeGuide, Fixr, contractor estimates, and building cost databases across multiple US regions (February 2026). Costs vary significantly by region, material choices, and local labor rates. ADU costs are particularly variable based on local impact fees and utility connection requirements.
Last updated: 2026-02-04
Frequently Asked Questions
How much does it cost to convert a garage to living space? +
A garage conversion typically costs $10,000–$50,000 depending on the scope. A basic living space runs $25–$50/sqft ($5,000–$10,000 for a single-car garage). Adding a half bath increases costs by $3,000–$8,000. A full ADU conversion with kitchen and bath ranges from $55,000–$160,000 for a double-car garage.
Do I need a permit to convert my garage? +
Yes, most cities require a building permit for garage conversions ($500–$2,000). Permits ensure code compliance for electrical, plumbing, insulation, and egress requirements. ADU conversions have additional zoning requirements. Unpermitted work can result in fines, insurance issues, and problems when selling your home.
How long does a garage conversion take? +
A basic garage conversion takes 4–8 weeks. Projects with bathrooms or HVAC extend to 8–12 weeks. ADU conversions take 12–24 weeks due to additional inspections, utility connections, and complexity. Permit approval typically adds 2–6 weeks before construction can begin.
What's the difference between a garage conversion and an ADU? +
A standard garage conversion creates additional living space attached to your home. An ADU (Accessory Dwelling Unit) is a self-contained living unit with its own kitchen, bathroom, and separate entrance that can be rented. ADUs require more extensive work ($100–$300/sqft) and must meet stricter building codes but offer rental income potential.
What ROI can I expect from a garage conversion? +
Garage conversions typically return 50–80% of costs in added home value. Bedroom and office conversions in markets with high real estate prices may see better returns. ADUs offer the best ROI through rental income — monthly rents of $1,000–$2,500 can recoup costs in 5–10 years while adding significant property value.
What parts of a garage conversion can I DIY? +
DIY-friendly tasks include demolition, painting, flooring installation, and basic trim work. Electrical, plumbing, and HVAC require licensed professionals in most jurisdictions. Structural modifications and insulation also benefit from professional installation to meet code requirements and ensure safety.
What do I do with the garage door? +
You have three options: (1) Keep it for future conversion back to garage ($0), (2) Replace with a wall and matching siding ($1,500–$5,000), or (3) Install a glass door system for natural light ($3,000–$8,000). The wall option provides the best insulation and appearance but limits future flexibility.
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