Review Zoning and Setbacks
2-4 hoursVerify local ADU rules, parking replacement, ceiling height minimums, and egress window requirements.
Advanced6-12 weeks
Garage Conversion Guide
Free step-by-step garage conversion for homeowners. Plan garage conversion with calculators and checklists covering review zoning and setbacks, plan.
homeownersADU builderscontractors
Workflow
Plan Insulation and Framing
1-2 daysDesign stud walls, raised floor platform over slab, and R-value targets for walls and ceiling.
Estimate Finish Materials
4-8 hoursCalculate drywall, paint, flooring, and trim for converted living area.
Schedule MEP and Final Inspection
1-2 weeksComplete electrical, plumbing if added, insulation inspection, and certificate of occupancy path.
Tools Used
- Drywall CalculatorPrimary
Estimate drywall sheets for new interior walls and ceiling.
- Paint CalculatorSupporting
Calculate paint for walls and ceiling after drywall finish.
- Concrete CalculatorReference
Estimate vapor barrier and sleeper layout over existing slab.
- Concrete Masonry CalculatorPrimary
Track conversion costs vs local ADU rental income potential.
- Staircase CalculatorReference
Verify any step transitions from house to converted floor level.
Checklist
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Planning
Safety
Envelope
Materials
MEP
Compliance
Reference Materials
Garage ADU Code Checklist (US)Table
Common IRC requirements for habitable garage conversions.
| Requirement | Typical Code | Action |
|---|---|---|
| Ceiling height | 7 ft 6 in min | Raise floor or modify roof |
| Egress | 5.7 sq ft window | Cut opening or add door |
| Fire separation | 1/2 in drywall min | Rate shared wall |
| HVAC | Heat to 68 F | Mini-split or extend system |
Insulation R-Value TargetsStandard
Recommended thermal values for garage conversion climates.
Don't Skip the Vapor Barrier
Slab moisture wicks into flooring — rigid foam and sealed plywood platform prevent mold.
Mini-Splits Beat Duct Extensions
Extending central HVAC into a garage often undersizes the main system; dedicated mini-split is cleaner.
Photograph Before Closing Walls
Document wire and pipe locations for future remodels.
Safety Notes
- Garage conversions require CO and smoke detectors — fuel-fired appliances in adjacent spaces need sealed penetrations.
- Never remove garage door track without infilling opening to match wall fire rating.