The current generation of building energy codes was born in the 1970s and 1980s, amidst a backdrop of the 1973 Arab Oil Embargo and the perception
of limited worldwide energy resources. The intent of energy codes has been rooted in conservation of resources. Several factors including global climate change
and the shale gas revolution have changed the picture fundamentally. It now has become critical that energy codes must reduce carbon emissions from the
buildings sector. This paper follows upon a recently published paper examining how climate policy now impacts energy code policy. A variety of drivers,
including greenhouse gas emission goals, regulation, market forces, and new technologies, is changing the relationship between buildings and the grid. As
this relationship evolves, it is increasingly important to find metrics that enable useful and clear comparisons at the national level, while remaining regionally
relevant. Similarly, it is increasingly important to move beyond annual metrics and find a way to consider hourly or other granular time scale impacts. Some
leading jurisdictions, including California and New York, are currently working to resolve these issues; this paper includes an examination of those ongoing
efforts. By encouraging building designers to consider hourly and regional building-grid implications, these metrics can support more distributed generation
integration and reduced carbon impacts. This provides a benefit to the building and also enables the building to support the grid. Through updating the code
basis metrics for buildings, model energy codes can play an important role in achieving jurisdictional carbon goals. This paper lays out new metric terms for
model energy codes to move beyond their current basis and better align with current and future priorities, including consideration of the impacts and mechanics
of those metrics. The authors provide specific recommendations concerning model code basis options, metrics, and mechanics; consider technical challenges to
implementation and some potential solutions; and discuss first-order impacts that these code basis considerations may have on building design.