Conversion to ADU: Attached ADU Title 24 Reports and Energy Calculations

For attached ADUs or JADUs, which are connected to the existing dwelling with common walls, ceilings, or floors, Title 24 compliance and energy calculations encompass various scenarios:

• “ADU Addition”: Involves the creation of a new ADU or conversion of existing unconditioned spaces (such as attached garages or basements) into ADUs.
• “ADU Alteration”: Encompasses the transformation of previously conditioned spaces, often part of the existing living area, into ADUs.
• “ADU Addition+Alteration”: Combines the construction of newly conditioned spaces with the conversion of existing conditioned areas.

Key Points for Attached ADUs:

• No solar PV requirements.
• Existing walls and extensions of existing walls are exempt from rigid insulation requirements if the proposed insulation is R-15 or greater.
• All ADUs, considered new dwelling units, must adhere to IAQ (Indoor Air Quality) ventilation requirements, regardless of size, with no exceptions.

Examples of ADU Scenarios:

• “ADU Addition” Examples:
  • Building a new ADU with a common wall shared with an existing home.
  • Transforming an existing attached, unconditioned garage into an ADU.
• “ADU Alteration” Examples:
  • Converting existing conditioned spaces, such as conditioned basements, into ADUs or JADUs.
  • Adapting existing living rooms into ADUs or JADUs.
• “ADU Alteration+Addition” Examples:
  • Combining the conversion of existing living rooms into ADUs with the construction of new living areas.
  • Transforming existing living rooms into ADUs while also converting a garage.

Explore Additional ADU Scenarios:

• Detached ADU
• Newly Constructed ADU

These scenarios help define the specific Title 24 compliance requirements for attached ADUs, ensuring energy efficiency and flexibility for different project types.