Click here for the Energy Star National Design Temperatures :

​https://www.energystar.gov/ia/partners/bldrs_lenders_raters/downloads/Design_Temperature_Limit_Reference_Guide.pdf?df3d-1d3a

Aslo:  Nationwide list of Window and insulation requirements for new homes:

​https://www.efficientwindows.org/codes2018/

​​Manual J Load Calculation Services   Load Calculation Service  aka heat load services