PHIUS+ 2021 Prescriptive Calculator  
 
 
      State  
 
      City  
 
      ASHRAE Climate Zone    
 
iCFA (ft2)
 
 
Number of Bedrooms
 
 
    *iCFA and bedrooms per dwelling unit  
 
Number of Stories
 
 
    4. SOLAR PROTECTION  
 
    4.1.1  Maximum Whole Window SHGC        
    4.4.1  Projection Factor for Fixed Overhangs        
 
    5. HEAT TRANSMISSION  
 
    5.1.1a  Fenestration/Openings Maximum U-Value     (BTU/h.ft2.°F)  
    5.1.1b  Walls & Overhang Floors Minimum Effective R-Value     (ft2.°F.h/BTU)  
    5.1.1c  Roofs, Ceilings Minimum Effective R-Value     (ft2.°F.h/BTU)  
    5.1.1d  Floors Minimum Effective R-Value     (ft2.°F.h/BTU)  
 
    6. MOISTURE RISK LIMITATION  
 
    6.2.1  Fenestration Condensation Resistance, Minimum fRsi        
 
    7. MECHANICAL VENTILATION  
 
    7.1.1  Minimum Sensible Recovery Efficiency, Heating Mode        
    7.1.3  Minimum Total Recovery Efficiency, Cooling Mode        
    7.1.5  Maximum Length of Fresh Air Duct to Outside      ft each  
 
    8. MECHANICAL SYSTEMS  
 
    Select System Type
     
 
    8.2  System Efficiency Minimum HSPF        
           
    Minimum SEER         
    Minimum EER        
 
    9. LIGHTING  
                 
      Average brightness      Lumens/Lamp  
      Number of Lamps         
    9.1.1.1a  Minimum Average Required Efficacy     Lumens/Watt  
 
 
*NR = No Requirement