ASHRAE 90.2-2024

ASHRAE/IES Standard 90.2 establishes whole-building design requirements that enable high levels of energy performance and greenhouse gas emission performance for residential buildings.

Updates to the 2024 edition include:

• New Title, Purpose, and Scope
  • The new title clarifies that Standard 90.2 addresses not only energy efficiency but also energy performance, including emissions and indoor environmental quality (IEQ).
  • The scope is expanded to cover multifamily residential buildings of any height.
• New performance requirements for substantial energy alterations (retrofits)
• Changes to clarify the differences between dwelling units and common areas, and their respective requirements
  • New lighting control requirements for common areas distinct from dwelling units
  • New thermal envelope requirements to specifically address common areas
• Changes to extend energy efficiency requirements that reduce net building energy consumption by approximately half as a stepping stone to net zero energy and net zero carbon emissions design and operation
  • New limits for the maximum Energy Rating Index (ERI) and CO2e Rating Index (CRI) consistent with the most ambitious recommendations of national and international organizations
  • Thresholds for the ERI and CRI (not counting renewable energy) when renewable energy systems are utilized on- or off-site to ensure that the use of renewable energy does not compromise efficiency
  • New provisions for jurisdictions wanting to enforce net zero energy and zero carbon requirements
• Increases in stringency for air leakage requirements
• Expansion of IEQ requirements to create greater alignment with ASHRAE Standard 62.2
  • This revision promotes the harmonization of energy efficiency and IEQ requirements.
• Updates to lighting requirements:
  • Improvements to lighting quality with the use of dim-to-warm and tunable light sources
  • Higher-efficacy requirements for permanent lighting and more detailed requirements for lighting controls in common areas
• New requirements for the provision of charging infrastructure for electric vehicles (EVs)
  • Standard 90.2 compliance now requires every parking space to have EV supply equipment installed or be equipped with the electrical connections of an EV-ready space for future installation.