ADU and JADU: All Answers

Accessory dwelling units: checklists by type, classification, solar, heating, testing, water heating and the envelope. Pick the question closest to yours.

Checklists by ADU type

1. Attached ADU Title 24 Report
2. Does a JADU Need a Title 24 Report?
3. Does a Garage Conversion ADU Need Title 24?
4. Attached ADU Title 24 Checklist
5. Junior ADU (JADU) Title 24 Checklist
6. New Detached ADU Title 24 Checklist
7. Garage Conversion ADU Title 24 Checklist

How the code classifies your ADU

1. Does a Prefab ADU Need Title 24?
2. California ADU Rules and Title 24
3. Do Pre-Approved ADU Plans Come With Title 24?
4. Two-Story ADU Title 24 Requirements
5. ADU Over a Garage: Floor Insulation and Title 24
6. Prefab and Factory-Built ADU Title 24 Requirements
7. ADU Alteration vs Addition: Which Title 24 Rules Apply?
8. ADU Addition vs New Construction: Which Title 24 Rules Apply?
9. ADU Attached to a Garage: How Title 24 Classifies the Project

Solar and battery

1. Does an ADU Need Solar Under Title 24?
2. ADU Battery-Ready Requirements Under the 2025 Energy Code
3. ADU Solar Exceptions and Exemptions Under the 2025 Energy Code
4. Can Existing Solar Panels Count for a New ADU?
5. Can New ADU Solar Panels Be Added to the Main House System?

Heat pumps and mini-splits

1. ADU Heat Pump Requirements in California for 2026 Permits
2. Can a New ADU Use a Gas Furnace?
3. Can an ADU Use a Mini-Split Heat Pump?
4. ADU Heat Pump Water Heater Requirements
5. Ducted vs Ductless Mini-Split for an ADU: Title 24 Differences

Testing and ventilation

1. Does an ADU Need HERS Registration?
2. ADU MERV 13 Filter Requirements
3. ADU Bathroom Exhaust Fan Requirements
4. ADU Kitchen Range Hood ECC Verification
5. ADU Whole-House Ventilation Requirements
6. ADU Airflow Verification: When Is It Required?
7. ADU Duct Leakage Testing: When Is It Required?
8. ADU Refrigerant Charge Verification: When Is It Required?

Water heaters and gas appliances

1. Can a New ADU Use a Gas Water Heater?
2. ADU Electric-Ready Requirements for Gas Appliances

Windows, insulation and roofs

1. ADU Window SHGC Requirements
2. ADU Wall Insulation Requirements
3. ADU Window U-Factor Requirements
4. ADU Skylight Requirements Under Title 24
5. ADU Attic and Roof Insulation Requirements
6. ADU Cool Roof Requirements by Climate Zone
7. ADU Slab Edge and Floor Insulation Requirements

Plans, cost and paperwork

1. What Is the CF1R for an ADU?
2. How Much Does an ADU Title 24 Report Cost?
3. What Plans Are Needed for an ADU Title 24 Report?
4. How Long Does an ADU Title 24 Report Take?
5. What If Plan Check Returns Title 24 Corrections on an ADU?

More answers

1. Title 24 for ADU Builders
2. Detached ADU Title 24 Report
3. Title 24 for an ADU Above a Garage
4. Do ADUs Need Title 24 in California?

Back to Permits and Compliance, or see the full Title 24 guide.